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Interesting + This just in from Rauch himself
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pentalab
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
RICH SEZ.... W8JI's censorship is quite rational, Bill. R L Measures, AG6K, 805.386.3734#### I had sent an e-mail to Rauch re: this PEP vs Average nonsense on the "other reflector". Other's had mentioned texts where they depict 14.5 db peak to average ratio in the male voice. I looked it up... it's also in "SSB sytems and circuits"... same deal.. 14.5 db. What every one missed was they are talking about absolute peak... as in ur 100 watt rms bulb is actually 200 peak.... and your 120 vac is actually 169.7 V. Peak V / dc resistnace = peak current. Peak current x peak V = peak watts.... that kinda peak. ### Reading though some audio engineering notes.. it was pointed out that a pure sinewave had a ... 3db peak to average ratio.... then the light bulb went on ! I tried the same experiment on my Behringer DEQ-2496 built in RTA... and sure enough, a sine wave has exactly 3db peak to rms ratio. When talking on my RE-27 mic... and looking at the raw audio on the RTA [b4 processing it with EQ, compression, split band limiter's, etc] I get EXACLY 14.5 db peak to rms ratio. This rta will hold the highest peak too... and in 1/10 db increments. ### How does this relate to ssb + linears ? While looking at my L4B's plate current meter.... with a dead cxr.. reads 800 Ma. While talking, it averages around 350-370ma... and 400-420 ma with the processing on. Looking at the Coaxial Dynamic's wattmeter... with a dead cxr... reads 1250 w. [whether meter is switched to average OR pep] While talking.[processor OFF]..and meter on average.... meter reads aprx 175- 200 w . Switch to pep.... reads 1400 w. With processor ON... pep readings are the same 1400 w pep. Switch to AVERAGE... and meter reads 250-265 w 1400 w pep / 250 average = 7.48 db IE: the average power output [250 w], is 7.48 db down from pep... and 7.48 db = 14.96 db peak. 14.96 db peak is virtually identical to the 14.5 db peak to rms ratio I measured on my audio rta in the 1st place !!!!! ### Imo.... the confusion arises between interpreting plate current readings while talking [with varying meter response time constants between different brands of linears/plate meter's].... and interpreting wattmeter readings, while talking... and wattmeter switched to "average". Of course, you can take 5 x different brands of wattmeter's... calibrate em all so they all read exactly 100 w with a dead cxr. Feed ssb into em [all 5 x wattmeter's on average... and all wired nose to tail]... and they all indicate differently ! Flip the processor on and off, and some average reading wattmeter's will show the increase in average more than other's ! Probably to read true average, a RF thermocouple ammeter would be the ticket. ### Below is Tom Rauch's response. Hi Jim, Please don't attempt to be civil to my face and a horse's ass in public about me on that Google amplifier hate group. Please be one way or the other. I have a rule where i treat people exactly the same behind their backs as I do in their face. I expect the same. Thanks, Tom ### Apparently Tom reads the posts here... and myself and other's must have either (a) pissed him off (b) he doesn't like criticism leveled at him (c) doesn't like "bad mouthing" about his Ameritron/ Heath/ Dentron /Amp supply/ MFJ 'engineering' or (d) doesn't like the idea that he will never post here, and can't do his own rebuttal (e) can't defend the superb engineering of Ameritron products.... like the AL-1500's 8 x lytics being run at their MAX + voltage ratings... then saying "that's ok" .... "just make sure the bleeder eq resistor's don't ever open up, or the lytics WILL start blowing up en masse" [If u ran the lytics at the prescribed 75% max V rating the manufacturer's recomend, they will NOT blow up, if the bleeder EQ resistor's open up.] ### Heck... anybody can read the posts, without being a member... they just can't post.. or see photo's, etc. He could log in with ANY user name... and ANY hotmail address. My guess is... he is probably among us right now. ### Here's my reply to Tom... dated a few day's ago. ### agreed. The other group isn't any hate group.... it runs just fine since day 1. You are free to join in any time you want. Loads of pix on there too. ### I use some of your insights as examples from time to time... like the test jigs for testing 3-500Z's for shorts... tripped leds the next AM..stuff like that. ### In the case of poorly designed Palstar /Ameritron / anybody else's products... they are fair game. ### we all know who the secret administrator is now.... it's Joe Subich W4TV.... blatantly obvious now. ### Nothing is behind your back.... it's a public forum.... with 136 members.. and growing in leaps and bounds. ### If member's can't freely disagree or discuss things... what's the point ? Take care.... Jim VE7RF ####### On the surface, this doesn't appear to be a .. "Google amplifier hate group". This Tom Rauch scenario appears to be nothing more than... 'sour grapes'. Me, I could afford to go out and buy 6 x Ameritron's right now, cash.... but don't. If they were any good, I'd have a few of em here in 4 day's flat. I'm tired of fixing this crap for other fellows. I got fed up with what's available for amateur radio... decided to build it myself. Next trick was most of the various handbooks lack detail. I found 38 mistakes...so far [mostly typo's] in Orr's 23rd and latest edition [and still available]. And that's only a fraction of that book. The 2006 ARRL handbook has a poorly written section on tube amplifiers. Bought a few engineering text's as well. The fellows who wrote the latest edition of "SSB sytems and circuits" obviously have a 'hate on' for GG linears. If it's not grid driven, it's no good.. per the Collins engineers. [who wrote the book]. ### gave up on standard texts... and decided to undertake a long drawn out study of every last component in a GG linear, it's function, calculated peak/average voltage + current of everything.... do a series of bench tests... and prove one way or another new concepts. Several idea's were tried, some discarded, some although they work superbly, are way too complex, and would make construction, implementaion, and trbl shooting and repair more difficult. I call the 'whittling down' process...'the elimination program'. Don't stick 4 x sockets/tubes/chimney's/anode suppressor's in an amp..... when just one socketless tube will do the job. You don't stick 4 x engines under the hood of a car... u get a bigger engine to start with. Trying to split the drive 4 x equal ways, ditto with airflow, then 4 x independently adjustable regulated bias supplies... + 5 x switchable plate current shunts [individual + total] amounts to a nightmare in progress. [you require separate fil xfmr sec's as well] Trying to trbl shoot a multiple tube amp with one bad int tube is a horror show. ## The short of it, with a HB amp... or at least a modified commercial unit... you can get some satisfaction from the process. When u light the wick on a HB amp for the 1st time, get any bugs resolved... and watch the wattmeter get blown off the scale.. it's a feeling of imense personal accomplishment and achievement. You don't get that with stock commercial units. ### I'm trying to convince W7IUV to resurect his 'amp pix page' from years ago. That alone inspired more people than anything else imo. It had 10's of thousands of hits from around the planet... including US signal corps, Nasa, and other's. It really showcased what ham's were doing in their work shops... and no two looked alike. Outa here... stay tuned...... Jim VE7RF |
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On Oct 22, 2006, at 3:52 AM, pentalab wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:To me, that Is peak P.RICH SEZ.... W8JI's censorship is quite rational, Bill.R L Measures, AG6K, 805.386.3734#### I had sent an e-mail to Rauch re: this PEP vs Average Agreed, which is why 1500W-pep is 3000W-peak as measured on an oscilloscope and calculated from P = E^2 / R. When talking on my RE-27I would turn down the mic, gain if my pair of 3-500Zs indicated this much anode-I. and 400-420correctomundo We definitely do hate censorship, Tom. The current situation reminds me of a neighbor boy who wanted to play games at his house with other neighbor boys, but he makes up rules to help him win, and then gets mad because the other boys left. What a laugher. He pretends not to be the Administrator/censor, yet he knows the excuses why those who question his questionable technical statements get booted off of AMPS before it's announced. Exactly. Because the subject is so involved, a smart TX RF amplifier debater: 1. Keeps his mouth on standby unless he knows the area of discussion. 2. When he inevitably makes a blunder, he is blazingly quick to admit to it and thank whoever gave the correct analysis. 3. Does not declare that he is one of the "recognized experts". (c) doesn't like "bad mouthing" aboutMFJ has a rather well deserved reputation as the junkiest commercially built Hamstuff on this planet. I have heard numerous Hams refer to it as Mother F___ing Junk. Also, as I understand it, an MFJ "3000w" antenna tuner was the only one ever tested in the ARRL Lab to ignite at 900W. One of the best laughers I heard from Tom was his assertion that MHJ/Ameritron amps don't have a glitch-resistor because the filter caps they buy have so much ESR built right in that they can't produce enough peak current to damage a tube. orI hope he does post here. If Tom is not allowed to post here, I'm outta here. andI'll bet a medium pizza with 5 toppings that I can show an example where a 75% safety factor would cause a serious problem if a bleeder- R opened. good news Not a sound wager. The only thing we know for sure is that Tom is the first to provide the reasons (excuses) why someone got his posterior jackbooted off of AMPS, and that anyone there who questions Tom's technically questionable statements is stepping into deep feces. A discussion group that is not allowed to discuss certain things is very clearly meshugga/bananas/nuts. cheers, Jim R L Measures, AG6K, 805.386.3734 r@..., , rlm@..., www.somis.org |
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pentalab
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
his Ameritron/ Heath/ Dentron /Amp supply/ MFJ 'engineering' numerous Hams refer to it as Mother F___ing Junk. Also, as I understandit, an MFJ "3000w" antenna tuner was the only one ever tested in theARRL Lab to ignite at 900W.#### any idiot knows you can't use Delrin rod as a form for a roller inductor.... and even if you didn't.... when u went to test it for the 1st time... "in the lab".... it would melt in front of yours eyes ! They shoulda simply tested the prototype under worst case condx... 1st. Every one of em went back too. .. well, a few didn't.... talked to a fellow 3 weeks ago.. who just literally melted his one hr b4. One of the best laughers I heard from Tom was his assertionthat MHJ/Ameritron amps don't have a glitch-resistor because thefilter caps they buy have so much ESR built right in that they can'tproduce enough peak current to damage a tube.### I saw that too. Rauch figured 1 ohm per cap + 2 ohms for the plate choke = 10 ohms.... hence no glitch R required. Like KM1H said.... "a lot of water has passed under the bridge since ur days at heathkit, Tom" My new 2500 uf @ 450V caps are 50 Miliohm ESR.... EACH ! Plus a 10 A CCS ripple current rating [ @120 hz.... less at 360 hz] ### How ANY amp manufacturer can be SO cheap, as to exclude the Glitch R these days..... is just a cost cutting tight wad... out to enhance profits. If they went cheap there... ask urself... "where else did they cut corners". Ain't no corners left to cut on any Ameritron product..... they have all been chopped out. ### He will be allowed to post here... nobody is stopping him...orI hope he does post here. If Tom is not allowed to post here, I'm [except W8JI]. This is an uncensored forum remember ? My guess is, without his.... 'groupies' to come here with him.... we will all pounce on him... and eat his lunch ! He wouldn't last 10 minutes here... or any other uncensored group. blowingand up, ifup en masse" [If u ran the lytics at the prescribed 75% example where a 75% safety factor would cause a serious problem ifthe bleeder EQ resistor's open up.]I'll bet a medium pizza with 5 toppings that I can show an a bleeder- R opened. ### U may well be correct IF the caps were badly mismatched in UF to start with. Now you would think Ameritron would buy em 10,000 at a time... in 5-10% Tol... then pay some new employee min wage to play.... "match up the caps in groups of 8". Heck, I believe Harbach matched up all his caps b4 shipping. ### also.. My idea of adding a 2nd 100K resistor across each cap is flawed. If just one of the PAIR of resistors opened up.. the V would skyrocket on that cap... regardless of the number of caps in the string. In fact... that one cap would have DOUBLE the V of the remaining intact caps/resistor's. IMO.. 1 x resistor per cap... that's it. THEN, if any resistor let go... V would divide according to each caps UF... with the caps with the highest UF getting the most V. Joe### we all know who the secret administrator is now.... it's isSubich W4TV.... blatantly obvious now.Not a sound wager. The only thing we know for sure is that Tom the first to provide the reasons (excuses) why someone got hisquestions Tom's technically questionable statements is stepping into deepfeces. ### Partially agreed. There is absolutely NO reason for the administrator's identity to be kept secret.... unless he's W8JI in disguise.... which would make a mockery of the 'amp' reflector. What's this secret administrator worried about... threats, lynching's ? Perhaps he was 'appointed' by the CIA.. or maybe Riley H himself ? Who ever he is... he's a hypocrite. Later... Jim VE7RF |
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FRANCIS CARCIA
Made From Junk 3000 watt tuner is designed to weed out all the QRO operators and make them pay for their sins -...- and pay big.
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Show quoted text
pentalab wrote:
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On Oct 22, 2006, at 7:39 AM, pentalab wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:Oren Elliot mfg the roller inductor. .. and even if you didn't.... when u went to test900w into a "3000w" tuner is hardly a worst case, Jim. Every one of em went back too. ..I will say nothing at all unless he drops the ball. He wouldn't last 10My guess is that he could if he could ever park his Hubrismobile. There goes the pizza.blowingand IF the caps were badly mismatched inNot even with 1% matched. Now you would think Ameritron would buy emIn the last batch of 104 Matsushita/Panasonic, 105?C, 560uF, 450v, 35mm x 51mm low ESR caps we stocked, the cap-to-cap variation was under +/¨C 4%. Shocking! .Agreed. We have sold over 12k Matsushita, 3W, 100k-ohm MOF resistors, so far there have been zero reported failures, and ther is typically <0.3% variation in measured R in the same 1000-unit box. . If just one of the PAIR of resistors opened up.. theIf there were two R-equalized caps in the string, V would eventually double where one R opened. In fact... that one cap would have DOUBLE the VWith 8 caps, opening one equalizer -R would eventually increase the voltage at the open R's cap by 8x. IMO.. 1 x resistor perEventually there would be 0v on all the caps with intact equalizer/ bleeder resistors and 100% of the voltage on the cap with the open R. Of course the potential would never get there since electrolytics tend to go BANG with not much of a surge in voltage. * Did *### Partially agreed. There is absolutely NO reason for the### we all know who the secret administrator is now.... it'sNot a sound wager. The only thing we know for sure is that Tom is make a mockery of the 'amp'Being fingered as a guy who can't stand to have his stuff scrutinized. When he phoned me about retrofitting his 922, I found Riley Hollingsworth to be a rather pleasant guy to converse with. Who ever he is... he's a hypocrite.He provides no callsign yet he jackboots participants who don't provide him with their callsign. Guffaw. R L Measures, AG6K, 805.386.3734 r@..., , rlm@..., www.somis.org |
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craxd
See below;
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
Oren Elliott changed the design of the coil form using another material after this happened. I remember e-mailing Steve Elliott about this and he mentioned them changing it. When they designed the coil, they didn't check it at RF frequencies. Evidently, they didn't have anything there to test at high power with at the time, if I remember the conversation correctly. Anyhow, they're safe for use now. The problem here sounds to me like MFJ continued selling the tuners with the delrin form inductors after knowing them to be bad. It also says the MFJ must have NEVER tested the tuner under full power before they started building them! Any good manufacturer would have delayed the sales and shipment until new replacement inductors could be installed. It sounds to me like they sent them out hoping some would make it. The ones that didn't, simply send a new inductor and get out of the labor. That is unless it failed under warranty and they had to do the labor. It still sounds an awful lot like a bunch of penny penching happened. of.. and even if you didn't.... when u went to test foryours eyes ! They shoulda simply tested the prototype under900w into a "3000w" tuner is hardly a worst case, Jim. currentthe plate choke = 10 ohms.... hence no glitch R required. therating [ @120 hz.... less at 360 hz] toGlitch R these days..... is just a cost cutting tight wad... out choppedenhance profits. If they went cheap there... ask out. Even the CB amp builders that made the better built amps used glitch resistors. One would think that if they would use them, an amateur radio manufacturer would surely spend the money to use them. When you buy a large quantity like they would have, the cost drops a good bit. guess### He will be allowed to post here... nobody is stopping him...orI hope he does post here. If Tom is not allowed to post here, I'm willis, without his.... 'groupies' to come here with him.... we ifall pounce on him... and eat his lunch !I will say nothing at all unless he drops the ball.He wouldn't last 10My guess is that he could if he could ever park his Hubrismobile. Heck, Ia bleeder- R opened.There goes the pizza. capbelieve Harbach matched up all his caps b4 shippingIn the last batch of 104 Matsushita/Panasonic, 105?C, 560uF, 450v, isis flawed.Agreed. We have sold over 12k Matsushita, 3W, 100k-ohm MOF typically <0.3% variation in measured R in the same 1000-unitbox. . capsIf just one of the PAIR of resistors opened up.. the eventuallyin the string.If there were two R-equalized caps in the string, V would double where one R opened.theIn fact... that one cap would have DOUBLE the VWith 8 caps, opening one equalizer -R would eventually increase voltage at the open R's cap by 8x.highestIMO.. 1 x resistor per electrolyticsUF getting the most V.Eventually there would be 0v on all the caps with intact equalizer/ tend to go BANG with not much of a surge in voltage.is### we all know who the secret administrator is now.... it'sNot a sound wager. The only thing we know for sure is that Tom questionsthe first to provide the reasons (excuses) why someone got his scrutinized.* Did *Tom's technically questionable statements is stepping into deep### Partially agreed. There is absolutely NO reason for the When he phoned me about retrofitting his 922, I found Riley Best, Will |
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craxd
Jim,
It's a wonder Tom didn't add a "by the way" saying, scopes and dip meters are very inaccurate and should never be used. : ) At least he answered you by e-mail, he never would me. If a scope is calibrated properly, or a dip meter the same, they can't lie. They can only show you the truth. If a dip meter shows a resonance, there is a resonance at its tuned frequency. Forget reading the freq off the dial, simply couple it to a known accurate freq counter, it will show the truth if you want precision. A calibrated scope can only show a waveform that it produces from what it sees at the input jack. The only way to make it lie is to not calibrate it or set a control properly. If using a Tek or other quality scope, your viewing something pretty accurate. I still think a scope is one of the better ways of measuring output power while monitoring the signal for over-modulation and cleanliness. This method has been used for years. I have an old book by Sylvania that they sold with their old tube type scopes showing all the ways of measuring the output power including the trapezoid pattern. I actually have a scope here made by Wawasee Electronics that uses the trap display, and it works pretty darn good. It's a combination wattmeter and scope. I also have one by Heathkit, but it really requires a connection to the modulation circuitry to work. The Wawasee one uses a yoke (electromagnet) to pull the trace over making the trap pattern. This doesn't require that connection and runs soley off the RF coming in. Either way, they both show the same pattern. Best, Will --- In ham_amplifiers@..., "pentalab" <jim.thomson@...> wrote: texts where they depict 14.5 db peak to average ratio in the malePeak V / dc resistnace = peak current. Peak current x peak V =RF thermocouple ammeter would be the ticket.if the bleeder EQ resistor's open up.]with ANY user name... and ANY hotmail address. My guess is... he isflat. I'm tired of fixing this crap for other fellows. I got fedbuild it myself. Next trick was most of the various handbooks lackcomplex, and would make construction, implementaion, and trbl shootingand repair more difficult. I call the 'whittling down'x engines under the hood of a car... u get a bigger engine to startand no two looked alike. |
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On Oct 22, 2006, at 5:20 PM, craxd wrote:
Jim,He did not tell me this via e-mail. He said dipmeters were worthless during a discussion of various means of grounding grids after a dipmeter measurement showed a result that contradicted his dicta about grounding grids. That IS the problem here. If a dip meter shows aCorrect. He didn't like the fact that an oscilloscope indicated a worst-case potential in a SB-220 that was only about 1/3 of what he predicted it would be. This potential is on the verge of arcing the Tune-C, so even if the voltage tried to rise much higher, the cap would zap and limit the voltage like a zener diode. The reason he wanted the potential to be higher was to explain away what I said was parasitic arcing by the SB-220's occasional 110MHz oscillation. The only way to make it lie is to notA calibrated oscilloscope is one way power meters can be calibrated, and it's much faster than using a bomb-calorimeter. However, an oscilloscope is as useless as tits on a boar hog for measuring cleanliness of a SSB signal. R L Measures, AG6K, 805.386.3734 r@..., , rlm@..., www.somis.org |
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On Oct 22, 2006, at 4:47 PM, craxd wrote:
See below;All they had to do is check the published D-factor for Delrin. ABS would have worked well around RF, but it's not as nice to turn down on a lathe. Evidently, they didn'tWhat material is used now? They saved pennies but they wasted dollars. That a mfg would advertise something as "3000W" without testing it at even 900W tells me to avoid purchasing their products. ... R L Measures, AG6K, 805.386.3734 r@..., , rlm@..., www.somis.org |
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pentalab
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
### well I guess Oren Elliot is an idiot then... so is MFJ. If they had half a brain... they woulda known Delrin is a no-no. You can tell it's Delrin from 8' away.... that stuff has a distinct look about it. front of.. and even if you didn't.... when u went to test ### agreed. I meant to say... bring it up from 0-3500 W cxr...yours eyes ! They shoulda simply tested the prototype under900w into a "3000w" tuner is hardly a worst case, Jim. with a high swr. IF it blows up b4 the 3500 w is reached... go back to the drawing board. Point is... you rate a tuner for 3 kw... it had better handle 3kw. Now tuner's are used by hams who have swr problems... and want the amp/gear happy. So 2- 3 kw into a 3 or 5 to one swr would be normal. [for a tuner rated at 3 kw.] If just a few guys ran 3 kw.... and a bunch more 2.5 kw.... and some rtty contest guys 1.5 kw... it had better work... with some headroom. Ceramic... OR steatite OR Micarta would have worked just fine..... so would thick wall hollow teflon tubing. Delrin is dirt cheap... comes in rods... from 1/16" up to 16" Diam, solid. No wonder they used it. Beware, some have used delrin for RFC's... then burnt the tops off... most last forever....depends on a lot of factors. [If u ran the lytics at the prescribed 75%problem ifup, ifmax V rating the manufacturer's recomend, they will NOT blowexample where a 75% safety factor would cause a seriousthe bleeder EQ resistor's open up.]I'll bet a medium pizza with 5 toppings that I can show an ### why is that??? Why wouldn't the V drop be proportional toa bleeder- R opened.There goes the pizza. UF [One eq resistor open up... the rest intact} cap is flawed..### also.. My idea of adding a 2nd 100K resistor across each is typically <0.3% variation in measured R in the same 1000-unit box. . ### Excellent.... what is the max DC voltage rating on them ??? I'm guessing 450-500 V ?? Put 8 of em on an AL-1500, and u got 450 V per resistor right there. caps in the string.If just one of the PAIR of resistors opened up.. the eventually double where one R opened. ## agreed. I'd say V would double ... asap...pronto. Perhaps u should add a section on ur site... about NOT adding a 2nd resistor per cap. The only justification for a 2nd string would be.. if the 2nd string of resistor's were wired in series, nose to tail... NOT connected ACROSS the lytics... but simply hooked across the B+ and B- [ 1st and last cap]. This would decrease bleed down time a bit... that's it. For an even faster bleed down time.... 50 k or even 25 k resistors as a bleeder, NOT eq resistor's could be added... or just 2-3 x big value wire wounds. IMO, in that config... IF the wirewounds ever opened up, u still got the eq resistor string. ### Back in my 4-1000 days... I'd just shut off the HV..everyting else on.... and simply hit the PTT... say nothing, no drive applied.... and when u go for idling current on the tube.... the idle current would suck the caps down to zero in a split second. Of course, after they are discharged... IF u then applied drive... the electrons would be attracted to the grid... and u would wrap the grid meter around the peg. On this latest project, the key line is routed through all the contactor's AUX contacts... including the step start contactor's aux contacts... so I can't key the amp with HV shut off. the voltage at the open R's cap by 8x.In fact... that one cap would have DOUBLE the VWith 8 caps, opening one equalizer -R would eventually increase ### why is that ?? With just one R per cap... and any one R opened up... there should be NO current flowing in the remaining 7 x intact R's. With 2 x R's per cap.... and one of the 16 x R's opened up... the cap with the open R would see exactly double the V as the remaining 7. Where ar u getting this 8 x from ?? What am I missing here ?? highest UF getting the most V.IMO.. 1 x resistor per equalizer/ bleeder resistors and 100% of the voltage on the cap with the open R. ### say what ?? Why would the cap with the open resistor take 100% of the plate V ?? [1 x resistor per cap] Of course the potential would never get there since electrolytics tend to go BANG with not much of a surge in voltage. ### I'll bite. When one cap goes BANG.... does it blow open... or short out? If it went open... no HV on remaining caps... if it shorted out... then it's just plate V / remaining caps. in the case of a L4B.. with 8 x 450 v caps.... even with 7 x remaining... it's STILL only 378 V per cap. On an Ameritron AL-1500.... with 7 x caps remaining.... it's 514 V per cap. Bye bye Ameritron caps. They would blow up like firecracker's. What's this secret administrator worried about...scrutinized. CIA.. ### Is Riley H gonna use his 922 for an IPA ?? We used to haveor maybe Riley H himself ?When he phoned me about retrofitting his 922, I found Riley these local Radio inspector's, who were also active hams... back in the 60's, 70's..... we called em... "the kilocycle cops". They were a real piece of work. later.... Jim VE7RF R L Measures, AG6K, 805.386.3734 |
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pentalab
--- In ham_amplifiers@..., "craxd" <craxd1@...> wrote:
theOren Elliot mfg the roller inductor. coil, they didn't check it at RF frequencies. Evidently, theydidn't have anything there to test at high power with at the time, if I remember the conversation correctly. Anyhow, they're safe for use now. ### what... no budget to test what u build ??? Probably no budget for... 'engineering' either. 1-2 ph calls, or just ask around would have saved em a lot of grief. Heck, they coulda just built 1-3 of em... shipped the 'prototypes' to Ameritron for testing.... let Ameritron blow up the tuner [and the AL-1500 driving it].... then informed em... that Delrin won't cut it. ### Even with the new material used... do you really think it will handle 3000 W ?? Dentron rated their tuner at 3 kw. My buddy had a 77-SX at the time.... and stuffed exactly 3 kw through it on RTTY..... vaporized the puny air-dux coil in seconds flat. The ant had a dead flat swr too... so the tuner was just..."matching" the already 50 ohm load. tuners with the delrin form inductors after knowing them to be bad. ### The dealer's were probably not informed... and kept on selling em... "yep, most pwerful tuner known to man, handles a full 3000 W too" . It also says the MFJ must have NEVER tested the tuner under full power before they started building them! ### Maybe they tested with 100 w pep ssb. Obviously they didn't try 900 W cxr.....idiot's ! Any good manufacturer would have delayed the sales and shipment until new replacement inductors could be installed. It sounds to me like they sent them out hoping somewould make it. The ones that didn't, simply send a new inductor and getout of the labor. That is unless it failed under warranty and they hadto do the labor. It still sounds an awful lot like a bunch of penny### agreed... some fellow with his sb-200 and 600 w pep may never see a problem.... then it gets sold... and 2nd buyer then proceeds to turn it into molten glop. At least Array Solutions puts a lifetime warranty on their stuff. Now, if u wanna see something built fairly heavy duty... take a look inside the Henry radio 10 kw CCS LP filter. 5.5" square x 10 " long.... 3/16" thick anodized AL... and stuffed with 8 x HT-57 15 KV NPO caps... Coils are 1/4", silver plated... and 20 kw 7-16 DIN connector's on each end..... a real bargain for the price... sits there and does nothing at 10 kw dead CXR on 10 m ! The 8 x caps alone are worth $320.00 For $290.00 new, it was a steal. Stuff like that isn't worth trying to HB. The cut off F is 33 mhz. glitch resistors. One would think that if they would use them, an amateur radio manufacturer would surely spend the money to use them. When you buy a large quantity like they would have, the cost drops a good bit. ### agreed Will. Eimac's AB-17, which has been around for eon's sez to USE a glitch R. A simple 50 ohm 50 w wire wound.. or a single 25 ohm 25 W or 2 x 25 ohm 25 w in series... would have done the trick in a AL-1500/ AL-1200, etc. Rauch has always been bragging how Ameritron buys this stuff dirt cheap.... cuz it's always 30,000 of this.... 40,000 of that, etc. I bet if you put out a tender for say 20,000 glitch R's [25 ohm 25 W]... and sent the tender to say dale, clarostat, ohmite, IRC, etc.... How much do u think u would pay ??? You could probably arrange to have XXX shipped every month as you need em... with some kinda kick back at the end of every fiscal year. ### The bottom line is... for NOT much more $$$, they coulda installed a glitch R, parasitic suppressor [AL-1500 doesn't have one] HV fuse, Gigavac vac relay, bigger HV rated lytics, larger value lytic HV filter caps,bigger ga wire on tank coils, etc. I'll bet, for a measly $40-$50 more... they coulda made there amps very reliable. It must be costing them and their dealer's a ton of money for warranty repair.... not to mention UPS destroying stuff coming /going. ### why doesn't somebody offer an amp in kit form these days ??? That would be the ticket. The end user would have a better idea how to repair it... since he built it in the 1st place ??? Later.......Jim VE7RF |
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On Oct 22, 2006, at 11:51 PM, pentalab wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:Example: In a series string of 4 electrolytic filter caps, with an... open bleeder on one cap, the potential on the other 3 caps would slowly bleed down to zero volts, and the voltage on the cap with the open bleeder would rise 4x to the full potential coming from the rectifiers. For example, a TL-922: It uses 4, 200uF, 500V caps in each half of a FWD. Normally there is c. 380v on each filter cap. If one bleeder/equalizer R opened, the potential across the cap with the open bleeder would rise to 4x normal or 1520v - but of course a 500v electrolytic would probably fail before the potential rose to 600v. 500V at 70?C.### Excellent.... what is the max DC voltage rating on them ???Agreed. We have sold over 12k Matsushita, 3W, 100k-ohm MOF.### also.. My idea of adding a 2nd 100K resistor across each Explained above. With just one R per cap... and any one RI was talking about 1 resistor per capacitor. Because direct current does not flow through a capacitor....### say what ?? Why would the cap with the open resistorIMO.. 1 x resistor perEventually there would be 0v on all the caps with intact correct In the only case I witnessed, the guts blew apart, the can shot up, and hit the 25' ceiling in the cal lab. It sounded like a 12ga shotgun. If it went open... no HV on remaining caps... if itnot when one disappears ...He didn't say. ...R L Measures, AG6K, 805.386.3734 r@..., , rlm@..., www.somis.org |
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Bill Turner
ORIGINAL MESSAGE:
On Mon, 23 Oct 2006 00:20:30 -0000, "craxd" <craxd1@...> wrote: If a dip meter shows a------------ REPLY FOLLOWS ------------ One needs to be careful with this. The typical single-tube or single-transistor dip meter can be pulled considerably off the true resonant frequency if coupling is very tight to a high-Q circuit. Just physically move the dip meter away far enough so the dip is barely perceptible and the accuracy will improve greatly. If you have used a dip meter much, you have no doubt had the experience of tuning slowly across the dip, and as you continue tuning have the dip suddenly disappear as the pulling effect disappears. Loose coupling will prevent this from happening. Bill, W6WRT |
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craxd
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
he worthlessanswered you by e-mail, he never would me.He did not tell me this via e-mail. He said dipmeters were during a discussion of various means of grounding grids after a No, I meant I wouldn't doubt that he would have said this to Jim. accurateThat IS the problem here. whatfreq counter, it will show the truth if you want precision. A heit sees at the input jack.Correct. He didn't like the fact that an oscilloscope indicated a predicted it would be. This potential is on the verge of arcingthe Tune-C, so even if the voltage tried to rise much higher, the capwas parasitic arcing by the SB-220's occasional 110MHz oscillation. The peak or peak to peak voltage one reads is exact, or within the scopes calibration limits. It's according to who calibrated it and the precision of the cal equipment that was used, but at least < = +/- 3%. thinkThe only way to make it lie is to not calibrated,a scope is one of the better ways of measuring output power whileA calibrated oscilloscope is one way power meters can be and it's much faster than using a bomb-calorimeter. However, an Well it's according to what you term clean. Harmonics no, unless you build or use a front end for this like the poor mans spectrum analyzer, or one of the commercial add-on units. Over modulation, hum, noise, regeneration, and parasitics can all be seen using a standard scope. In the Sylvania scope book they give the following; Modulation percentage either using the wave pattern or the trap pattern. Modulator output low, modulator mis-matched to RF stage. Regen in RF stage, plus low AF output or modulator mis-match. Low grid bias in RF stage, low excitatation, or both. RF stage modulated incompletely neutralized. Low excitation, low bias, or both in high-mu modulated RF stage. Driven parasitics in modulated RF stage. Hum modulation. Noise modulation. Modulation percentage or H2 - H1 / H2. H1 is the unmodulated height. Each of the above having a distinct pattern on the scope. All can contribute to one being un-clean. R L Measures, AG6K, 805.386.3734 Best, Will |
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craxd
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
wrote: thehis Ameritron/ Heath/ Dentron /Amp supply/ MFJ 'engineering'numerous theARRLOren Elliot mfg the roller inductor.Lab to ignite at 900W.#### any idiot knows you can't use Delrin rod as a form for a ABScoil, they didn't check it at RF frequencies.All they had to do is check the published D-factor for Delrin. would have worked well around RF, but it's not as nice to turndown on a lathe. I think they more or less took the suggestion from a plastics peddler saying that Delrin would for sure work in this application. I'll have to look up the difference in the D factor between Delrin and say Teflon, etc. I have the Modern Plastics Encyclopedia here, I've just not looked through it in a while. now.Evidently, they didn't
I can't remember if he even told me what they did change it to. Seems to me like they may mention it on their website. Also, there's several different designs you can get on these similar to the air variables like the brushes etc. Some cost a little more than others according to what you order. They also figure the buyer does the calculations to determine which size to buy, or at least know enough to. In caps, I just told them what model, shaft type, and air gap I wanted to place an order. It's similar for ordering their roller inductors. I'm pretty sure MFJ bought these direct as I used to buy direct from them. You don't need to buy large orders either, 1-2 pieces can be ordered. tuners alsowith the delrin form inductors after knowing them to be bad. It beforesays the MFJ must have NEVER tested the tuner under full power delayedthey started building them! Any good manufacturer would have wouldthe sales and shipment until new replacement inductors could be outmake it. The ones that didn't, simply send a new inductor and get had toof the labor. That is unless it failed under warranty and they tellsdo the labor. It still sounds an awful lot like a bunch of pennyThey saved pennies but they wasted dollars. That a mfg would me to avoid purchasing their products. That's the way I seen it too! ... |
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craxd
--- In ham_amplifiers@..., "pentalab" <jim.thomson@...>
wrote:
Not necessarily. MFJ could have blundered on the specs when ordering, or ignored some rated specs. I do know that Oren Elliott changed the form though, to which type I can't remember. You might take a look at OE's website, seems to me they might say what it is. In other words, they could have both blundered. This was Oren Elliots first time of manufacturing roller inductors. They use steatite on the air caps. Who knows, MFJ may have told Oren Elliott that Delrin would be what to use? MFJ was the first customer on these, and most likely was who told them they would buy them if they made them. Even at this, the OE products are still built better in my opinion than some made by others as far as the other components. Some of the cheapest stuff I've seen is by Palstar and some stuff that MFJ made themselves such as their air caps. The frames and brushes are pretty flimsy on them. Palstars roller inductors are made about the same as their air caps. Since OE changed the form material, they're the top of the line I think. If you dug into this, I'll about bet MFJ is who mentioned using Delrin and hooked OE up with a plastic supplier. I just know OE makes some pretty good air caps with a very good design. Best, Will |
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On Oct 24, 2006, at 9:05 PM, craxd wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:Porcine shampoo. I'm a guy who used to calibrate oscilloscopes.he But not SSB IMD. ...R L Measures, AG6K, 805.386.3734 r@..., , rlm@..., www.somis.org |
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craxd
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
dip leastmeters are very inaccurate and should never be used. : ) At aheworthlessanswered you by e-mail, he never would me.He did not tell me this via e-mail. He said dipmeters wereduring a discussion of various means of grounding grids after a Porcine shampoo. I'm a guy who used to calibrate oscilloscopes.worst-case potential in a SB-220 that was only about 1/3 of whathepredicted it would be. This potential is on the verge of arcingtheTune-C, so even if the voltage tried to rise much higher, the capwas Wouldn't you agree they're exact to within their tolerance? If the cal equipment used is correct, and the scope is ran in a similar enviroment temperature wise, etc, it should show close to the same as what it was calibrated to read. That is provided it's withing calibration and hasn't been tampered with. I'm not saying it's exact with no deviation, but it's one of the most exact ways we have reading an AC voltage. 3% or less tolerance is pretty darn good. According to the Tektronix manuals, they should be capable of better than 3%. calibrated youand it's much faster than using a bomb-calorimeter. However, an build or use a front end for this like the poor mans spectrumBut not SSB IMD. Best, Will |
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On Oct 25, 2006, at 1:04 PM, craxd wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:No. Exact means without error -- within tolerance means within a specified error. If the cal equipment used is correct, and the scope is ranCorrect -- which is not without error. That isR L Measures, AG6K, 805.386.3734 r@..., , rlm@..., www.somis.org |
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