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Grid Overcurrent Protection Module?
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Does anyone have a manual or schematic for the MFJ GOP-1 Grid Overcurrent Protection module?? A web search only comes up with high tension power line grid protection, etc., and MFJ's own manual search engine has been all but useless over the past few years. TNX, Steve K0XP
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6 Meter Amp WTB
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My search for info to convert my 2M Clipperton V amp to 6M not having received any replies... Anybody out west, say in Nevada, Arizona or possibly western NM, or perhaps as far north as Sacto, CA (within no more than about 2 day's driving distance of 29 Palms, CA) have a 6M amp for sale? I need at least 600W and preferably legal-limit.My budget is somewhat limited, tho... so unless it's a real Alpha 8406, I'd like to spend less than $1500. My other option is to convert one of my half-dozen HA-14 "Kompact KW" amps tp 6M; but I've never seen info on anybody who has successfully done that. (SB-200, sure... but not the similar HA-14). I tried it once and wasted several days trying to stop it from oscillating. Took off like a banshee on coke 8-O TNX, Steve K0XP
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Wanted: YC-156
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Hi, Looking for a spare YC-156 with good emission for my HF amp. Please respond with price, condition, and picture. Send email to beefus100@... Thanks, Jack, WB8BFS
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LK500-ZC Fan Thermal Switch
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I have just acquired an old Amp Supply LK500ZC amplifier. It has a few issues which I'm working my way through. One issue is that the cooling fan is on high speed all the time. I have just confirmed that the thermal switch, which is in the outlet air stream is shorted. This means that the series resistor which keeps the fan a bit slower and a lot quieter is bypassed by that switch, resulting in a lot of wind and noise. It is no problem to get a two legged TO26 type package N/O switch but I don't now what temperature I should go for. There is no indication on the original switch that I can see. The manual I downloaded is a general one for the LK400/500/550 series and does not include the 2 speed fan deatils of the LK500-ZC. So, I have 2 questions. 1. Was there a specific manual for the LK500ZC and where can I get a copy? 2. Does anybody know what temperature that thermal switch is? Thanks and 73, Alek VK6APK.
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King Conversions 6m Amp
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Yes I am one of those guys who has bought an amp and never used it. Have a King Conversions 6m Amp built on a SB-220 that has not been run since Lou W1QJ built it for me. By the time the amp was done I had an solid state amp that covered 6m, so it never has been used. $1000 plus shipping from 54220 (two boxes - tubes will ship separate) 73 Steve K9ZW Blog: http://k9zw.wordpress.com
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Hi All, I am new to the Group, a friend of mine suggested to ask my problem here as there are many capable Hams on this group. I have a GS35 on 2m and has been working for years, I have changed the tube during it's life and blown a bias transistor here and there. The problem I am having now is one I have never seen. When I apply HT to the Amp usually the Amp is cut-off with the cut-off resistor and no current flows. Now I get Negative Grid current and Anode current starts to flow, and the more I increase the Anode say from 1000v to 1500v the current increases. The things I have changed in the Amp: Tube - New tested good tube installed. Bias Board - tested adjustable from 0 to 55 v Filament Transformer HT & Heater feed-thru cap. Usually when the Grid Bias transistor goes - I am using a BDX66B from DL4MEA design ( https://www.qsl.net/dl4mea/2g35.htm ) the amp does not do anything so not sure that Bias is the problem. I anyone might have come across this negative grid current problem please let me know. 73 Philip 9H1PA
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Hi from the newbie.
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Hi all. I've acquired a new to me dead QRO 2500DX (S/N 5461) that looks really clean inside and out. It does power up and completes the warm up but no keying for XMIT. I'm just getting started diagnosing. Story goes, it was running fine when a "pop" was heard. Immediately shut down and a large dead spider was found inside. A "buddy that's a great tech" diagnosed as bad "protection" chip. I took a quick look and it appears he was referring to a plug in 555 timer DIP?? What is the street reputation for this amp? Does the story sound reasonable. Tips or Advise? BTW, both meter lamps are out. I'm hoping to retrofit leds?? TIA 73
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12KW CCS on 160-15m......using the 3CX-6000A7..... Part 26
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12KW CCS on 160-15m......using the 3CX-6000A7..... Part 26 Scott made some more progress today. Here the low voltage assemblies are finished. The completed assy drops in as one unit. Also mounted is the opto isolator to key the 4 x sped up vac relays in the RF deck. https://www.youtube.com/watch?v=xUgFiXsRCkE
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Jennings Relays ABB
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I see a lot of advertisements around for Jennings products. It seems the ABB group have taken over Jennings and are producing products like the RJ2B and the full Jennings lineup. Anyone used these new ABB/Jennings products from ABB THOMAS & BETTS? I cant seem to upload files in the files section. Henry
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2kd-5
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I am interested in the capacitor bank ship to 62948 Yahoo Mail: Search, Organize, Conquer
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12 KW CCS ON 160-15M....USING THE 3CX-6000A7..... PART 25
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Here, the soft start is wired up. Paralleled 25 ohm, 50 watt resistors used. Since there is a total of 125 uf for the filter cap assy, the step start has to be done very carefully, with the requisite delay...typ 5-10 seconds. 12.5 ohms is used because if say 25 ohms used....the B+ will come up to almost max, but won't reach max, since the magnetizing current on the paralleled plate xfmr's primary's will still flow through any step start resistor...creating a V drop across the step start resistor assy....so you never get the full 240 vac applied to the xfmr's primary. Once shunted, you end up with a secondary surge. To minimize the secondary surge, a lower value is used for the step start resistor assy. Regardless of value, when T=0, you always end up with the full 240 vac dropped across the resistor assy. Paralleled 4 ga teflon wire used. Mercury contactors used. I found a pair of 250 amp supercon connectors, cheap, on ebay, so notified Scott asap....and he snagged em. These go on the power cable ......and plugged into the mating (existing jacks) on the back of the HV supply. This supply gets a bit more complex, since the pair of identical 7.5 kva (5300 Vac) plate xfmr's will reside in a separate cabinet. The HV supply is getting there.....albeit slowly, due to time constraints. https://www.youtube.com/watch?v=-BpADwJMbOk Note you can turn on the close captioning...and also the entire transcript.
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I am doing some updating to my Alpha 76PA 3-tube amplifier. I have switched the T/R relay to a pair of vacuum relays and changed the "relay" (AKA Send or PTT) request to send from 24 Volts to be a compatible 12 Volts for modern transceivers. I am about to replace the original Alpha Plate Choke with a re-wound Ameritron style taller choke. While I'm at it I have a, new-but old, Cera-Mite 5000 PF, 15 KV door-knob capacitor. I'm planning to replace the original plate blocking capacitors with this door knob cap. The original plate blocking cap uses dual original 2000 PF, 6 KV ceramic disk capacitors. I've has this door knob cap a long time and I'm no longer planning on building a tube amplifier from scratch. As you can see I've fabricated two copper straps to place the cap in the 76pa amp. I fabricated these straps to put to door knob cap into a previous Alpha 76PA I had. And when fastened in place it is quite sturdy and has adequate clearance from its surroundings. This amplifier will be kept in my station as a back-up for my Solid State PA. I've found SSPAs to be less tolerant of operator errors than tube amps. But I still like the instant on and 6 meter capability in my current SSPA (403A/Flex PGXL). What are your thoughts on this replacement other than it is overkill in this situation? 73, Dave, w6de
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FS: SPE Expert 1.5K-FA in exceptional condition
On behalf of the estate of local KE5BR, available is an SPE Expert 1.5K amp in excellent condition. The amp was recently brought up to Series 2 specs with all factory updates being applied by Main Trading Company of Paris TX. Includes original box and documentation. $3500 cash, no trades. Pickup near Kansas City. Or for personal delivery at the Xenia Hamvention next week. Sorry, no shipping. All proceeds to the surviving XYL. Should you have interest in this amplifier, kindly contact me directly off list. And thank you for your consideration. -- 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com
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I¡¯m working on a used AL-811 for a friend. The 811 tubes were bad, so I replaced them with some Penta Labs 572b tubes (A whole another adventure). I also replaced the tube sockets, and installed GDTs on the tube sockets and added some bias diodes on the center tap of the transformer. I made sure there were not MOVs in the input board. The issue I¡¯m having is high SWR (over 2:1) on 80 meters and I can¡¯t get full drive from what appears as the exciter is folding back. All the other bands are fine. I¡¯ve attempted to adjust the 80-meter input coil with no effect on SWR/PWR in. I¡¯ve checked the input switch for continuity and from the input through the 80-meter input coil with no problems. Switch alignment looks good. I remove and tested C4 (for 80 Meters) a 500pF cap and it tested good. I¡¯ve removed the 200-ohm padding resistor just to see what effect it had on SWR and nothing. Obviously, I get more output for the same amount of drive. If I¡¯m at the high end of 75 meter with the tuning slug all the way at the end of the coil form, the SWR just starts to drop, and I see an improvement in drive level. With the padding resistor in circuit, I¡¯m showing about 50 watts for drive and 60mA of grid current. With the amp in bypass the radio will do 120W no SWR. I¡¯m wondering about values of C4 and if anyone else has experienced this behavior after swapping to 572b tubes? Don¡¯t know how the amp performed prior as the tube replacement. Thanks for any productive comments in advance. Jim ¨C AA7CL
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Clipperton V/144 MHz On 6M?
I've seen reference to a "6M Kit" for the Clipperton V 2 Meter amplifier (uses a single 4CX250B). Anybody have any pix or drawings of this conversion? It seems to me that this amplifier was essentially a copy of an article I saw in 73 Magazine way back in the late 60s or early 70s where the guy buillt a pretty compact amplifier using a 4X150A with a tank circuit that covered both bands, depending upon which output connector was connected to the antler; I think it was link-coupled on 144 MHz, but a conventional pi-net on 6M?? I don't rember what he did about the input circit. I have another 800W amp for 2M, so I'm thinking of converting this one to 6M instead. (And if I ever acquire an Alpha 8406, then I'll convert the Clipperton to 220! 8-) TNX, Steve K0XP
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Vernier Drive Replacement - Ameritron AL series amp
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Hello, Has anyone had to replace the vernier drive on the load control of any of the Ameritron AL series amplifiers? Thanks & 73, Garry - K4OR
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Canadian Marconi BH-100 SS KW
I have one of these Ill be selling at NearFEST this weekend. I have the technical manual. I also have a 50v50a switcher to power it. It needs love from a good tech. It is a beast when operational. 73 Gerry W1VE
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These tubes were literally dug up last weekend at a former "VHF Telegraphy" commercial site in the UK. Does anyone recognise what they are ? Ideally I'd like to know what equipment they were used in, date is likely 1960 - 1980, all the printing is lost to the rain/soil. Tim
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Hello I've already presented the refurbishment of this L7 amplifier here. I implemented a cathode bias and connected the grids directly to ground. I noticed that, regardless of the bias, I can't output more than 400 W. At 7.100 MHz ¡¤ The gain is 13 dB. ¡¤ The plate voltage under load is 2450 V. ¡¤ The plate current is 310 mA. ¡¤ How can I increase the output power? ¡¤ What do you notice on an amplifier equipped with 2 3-500Z tubes in parallel? -- F1AMM Fran?ois
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Harbach Electronics And Homebrew HF Amps
Harbach Electronics has started their own FB group. "This is a place for people to post pictures of their Harbach kit installs, Homebrew ham pa projects and brainstorm ideas". https://www.facebook.com/groups/1204552244652532 It's actually quite well done. The kits need a diagram, and some other minor tweaks in the documentation.
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Sat 8:39am
Sat 8:39am