Re: Ameritron AL-80 (Not A or B)
I'm curious, how much drive are you driving it with? Constant carrier drive? How much power out? Ig and Ip?? Bob W4JFA?
On Sun, Dec 10, 2023, 9:41 AM Nick Jones KC0YKO < kc0yko@...> wrote: All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
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There are 2 x chinese factories. One has a 12% failure rate.? The other has a 70% failure rate.? ?The good 3-500Z's all have the white base...and not the brown base.?
?
The 3-500Z's that Tom at CTR sells have gone through some exhaustive tests...to weed out the duds.? The tubes should have C measured from? anode to grid...and also grid to cathode, and anode to cathode.? ?Then hi-pot tested from anode to grid..and also grid to cathode.? ?Then the emission testing..to measure grid current vs anode current etc. .? Other tests include measuring cathode current (typ 14.5 amps).
?
The issue with chinese tubes is.... they typ hi pot test between grid to cathode...like 700-1000 vdc.? ?A good eimac? will hi pot test 5 kv? from grid to cathode.? ?A good tube should? hi-pot test 12-16 kv? between anode to grid.?
Typ chinese tubes have higher C between grid and cathode.... due to narrower spacing...hence the lower hi pot test results.? In typ operation, there is not a lot of peak V on the cathode.? ?100 watts pep into 50 ohms is only 70.7 vrms / 100 V peak.
?
The good chinese tubes will last a long time.? ?CTR tests em correctly.? The other tube dealers just sell em.... and it's? up to the end user to evaluate em.? ?That's fine too..as long as when there is an issue, the end user can return em / exchange em.
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Re: Ten-Tec Centurion Parts Needed
I may have what you are looking for.? This was built by Heyboer over 20 years ago, and I've never needed to use it.? Still in it's original shipping box.
contact me direct for more info
ron
KA3JIJ
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I have had good service from RF parts.? Ups broke the tube in shipping and it was replaced no issue
Brian
FWIW, contact Tom, W8JI at CTR Engineering.? From what I understand
he has tubes F/S that are tested by him to make sure they are
working.
73? Andy? K9ATX
On 12/10/2023 12:03 PM, Dave wrote:
Hello Group, I could use your help!
Looking to pick up a 3-500ZG replacement for my AL-80B.? My
choices are:
RF Parts Company: 3-500ZG (6-month warranty). 250$ (China)
DX Engineering: Penta Labs RF Vacuum Tube 3-500ZG (no warranty
listed). 300$ (assume China?)
DX Engineering:?Ameritron 3-500Z Replacement Power Tube (All
products manufactured by Ameritron have a one-year limited
warranty) 360$ (assume China?).
Both vendors have always been reliable for me so my question:
Is the Ameritron tube worth the additional $$ or is it branding?
Is the Penta Tube?worth the additional $$
What would be the best replacement?
(sorry for writing a novel)
Thanks in advance!
73
K5AKM - Dave
--
"Where the Old Soo crossed the New Soo"
Duplainville, Wisconsin
Web page:
Youtube Channel:
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I'll agree with VK4TUZ on good experience with RF parts.? I needed 2 3-500Z tubes for a Heathkit HL-2200 basket case that I restored.? After looking far and wide, I found all sorts of price variations and warnings.
My take away form the research was this.? All these tubes at the time came from a couple Chinese factories.? Way to tell which factory was whether the base of the tube was brown or white.? Neither factory made quality tubes, but the brown base tubes seemed to have a lower failure rate.? RF Parts, Matchlett and Penta Labs were all using and rebranding the brown base tubes.
But the big issue was and still is: if you buy direct at low prices you get no assessment of the tube quality.? If you buy from the US based outlet of Matchlett, Penta Labs and RF Parts you get a pre tested tube that is guaranteed to be operational and carries a warranty.? Buying direct you get a "pig in a poke" that might be good or might be junk because it has never been tested.
Learned this the hard way trying to cheap out on a set of 811A's.? Bought direct and had a 50% out of the box failure.? Spent months trying to get replacements and eventually gave up.
After that, RF Parts became my go to source for power tubes.
ron
KA3JIJ
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FWIW, contact Tom, W8JI at CTR Engineering.? From what I understand
he has tubes F/S that are tested by him to make sure they are
working.
73? Andy? K9ATX
On 12/10/2023 12:03 PM, Dave wrote:
Hello Group, I could use your help!
Looking to pick up a 3-500ZG replacement for my AL-80B.? My
choices are:
RF Parts Company: 3-500ZG (6-month warranty). 250$ (China)
DX Engineering: Penta Labs RF Vacuum Tube 3-500ZG (no warranty
listed). 300$ (assume China?)
DX Engineering:?Ameritron 3-500Z Replacement Power Tube (All
products manufactured by Ameritron have a one-year limited
warranty) 360$ (assume China?).
Both vendors have always been reliable for me so my question:
Is the Ameritron tube worth the additional $$ or is it branding?
Is the Penta Tube?worth the additional $$
What would be the best replacement?
(sorry for writing a novel)
Thanks in advance!
73
K5AKM - Dave
--
"Where the Old Soo crossed the New Soo"
Duplainville, Wisconsin
Web page:
Youtube Channel:
|
Hello Group, I could use your help!
Looking to pick up a 3-500ZG replacement for my AL-80B.? My choices are:
RF Parts Company: 3-500ZG (6-month warranty). 250$ (China)
DX Engineering: Penta Labs RF Vacuum Tube 3-500ZG (no warranty listed). 300$ (assume China?)
DX Engineering:?Ameritron 3-500Z Replacement Power Tube (All products manufactured by Ameritron have a one-year limited warranty) 360$ (assume China?).
Both vendors have always been reliable for me so my question:
Is the Ameritron tube worth the additional $$ or is it branding?
Is the Penta Tube?worth the additional $$
What would be the best replacement?
(sorry for writing a novel)
Thanks in advance!
73
K5AKM - Dave
|
Re: Ten-Tec Centurion Parts Needed
Sorry, I don't have any transformers for the 30L-1. Tom
Hi Tom,? I am looking for a transformer for a 30L1 amp that I am repairing for a SK's widow.? The current one appears to have a short and blows fuses.? You mentioned having Collins parts.?? Any suggestions?
73,? Bill K3HZP
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Collins transformers for the 30L-1
Bill K3HZP,
Contact Heyboer, they have all the PWDahl specs and can build a PWDP13170 cheaper than a rewind. They did a Globe King 500A modulation transformer for me and it's great.
73 Bill N4LG
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At 12:29 PM 12/10/2023, Nick Jones KC0YKO wrote: Nationwide radio has a good selection of Collins transformers but it looks like they currently do not have one for the 30L-1.
Peter Dahl makes a replacement p/n
PWDP13170
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73 Nick KC0YKO
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Re: Ten-Tec Centurion Parts Needed
Nationwide radio has a good selection of Collins transformers but it looks like they currently do not have one for the 30L-1.
Peter Dahl makes a replacement p/n?
PWDP13170
--
73 Nick KC0YKO
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Re: Ten-Tec Centurion Parts Needed
Hi Tom,? I am looking for a transformer for a 30L1 amp that I am repairing for a SK's widow.? The current one appears to have a short and blows fuses.? You mentioned having Collins parts.?? Any suggestions?
73,? Bill K3HZP
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Re: Ameritron AL-80 (Not A or B)
Thanks for all of the reply. I will check the connections within the tank circuit. The band switch looks OK but I will investigate closer. Band switch is in the correct position when testing.
--
73 Nick KC0YKO
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Re: Ameritron AL-80 (Not A or B)
Is the band switch in good condition, in the correct position?
On Sunday, December 10, 2023 at 09:41:10 AM EST, Nick Jones KC0YKO <kc0yko@...> wrote:
All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
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Re: Ameritron AL-80 (Not A or B)
Nick,it seems as though you may have a poor connection somewhere inside the realm of the tank circuit. ?This could be at the band switch, the connections of the coils to the variables or just about anywhere, so make sure of all mechanical and soldered connections. ?Above 4 meters there are no padding cap issues so it¡¯s got to be something like that. ?Also be sure there is no slippage on any of the connections to the variable capacitor shafis! ?Good luck
On Sunday, December 10, 2023, 9:41 AM, Nick Jones KC0YKO <kc0yko@...> wrote: All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
|
Ameritron AL-80 (Not A or B)
All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
|
Re: Ten-Tec Centurion Parts Needed
¡°Although it¡¯s a handsome looking amp it¡¯s certainly not the best performer in its class. ?It lacks inductance on 160 and the tank isn¡¯t so good on 15 and 10¡±. ? So true, Louis. As Jim VE7RF also told me, my Emtron DX-2SP had the exact same issues on the low bands, but especially on 15, 12 and 10m. After a few years of 1200-1500W FT8 operation, my 10m and 15/12m tank coil tap flexible soldered silver plated conductors were black and the two connections to the tank coil had gone¡..bad. I re-made these two connections with 8mm flat silver plated copper conductor, held in place with tightening brass screws onto the tank coil and silver solder to make sure. Luckily, my band switch was unaffected by the high circulating currents. I added inductance on the toroidal tank inductor by moving the tap an additional 3 turns for 80m. This improved the efficiency up to around 60% (was below 40%) on 80m. Then I added some fixed loading capacitance on 160m which raised the efficiency on 160m from around 30% up to 50%. All of our Ham multi-band amps have these same problems, but they are solvable with a little help from the experts on here. ? My Emtron is now working well on all bands. ? Cheers, ? John VK6JX ?
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From: [email protected] <[email protected]> On Behalf Of Louis Parascondola via groups.io
Sent: Sunday, December 10, 2023 1:10 PM
To: [email protected]
Subject: Re: [ham-amplifiers] Ten-Tec Centurion Parts Needed? TenTec buit?their own variable capacitors. ?So their plates are unlike any others. ?I have some plates and if you want you?ship me the cap I¡¯ll rebuild it for you. ?I should have a few plates left. ?Although it¡¯s a handsome looking amp it¡¯s certainly not the best performer in its class. ?It lacks inductance on 160 and the tank isn¡¯t so hood on 15 and 10. ?
? On Saturday, December 9, 2023, 6:51 PM, Tom Hess <Tomhess8@...> wrote: I have a lot of parts for amplifiers and stuff. I handle estates for the local ham club and have? processed estates for several Collins Radio engineers. They collected lots of parts over the years. I don't have any experience with the Centurion, so I don't know what your parts look like. Please send a photo of the switch and specs?for the capacitor - size, value, voltage. ? On Sat, Dec 9, 2023 at 9:42?AM Omni <selcor@...> wrote: I have recently acquired a Ten-Tec Centurion model 422 that is in very nice condition, but has a blown up bandswitch and the plate tuning capacitor was arced.? I might be able to salvage the capacitor, but the bandswich will need to be rebuilt or replaced.? If anyone has a switch/parts and/or a capacitor please contact me off list to let me know what you have.
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Re: Ten-Tec Centurion Parts Needed
TenTec buit?their own variable capacitors. ?So their plates are unlike any others. ?I have some plates and if you want you?ship me the cap I¡¯ll rebuild it for you. ?I should have a few plates left. ?Although it¡¯s a handsome looking amp it¡¯s certainly not the best performer in its class. ?It lacks inductance on 160 and the tank isn¡¯t so hood on 15 and 10. ?
On Saturday, December 9, 2023, 6:51 PM, Tom Hess <Tomhess8@...> wrote: I have a lot of parts for amplifiers and stuff. I handle estates for the local ham club and have? processed estates for several Collins Radio engineers. They collected lots of parts over the years. I don't have any experience with the Centurion, so I don't know what your parts look like. Please send a photo of the switch and specs?for the capacitor - size, value, voltage. Tom KD0HF On Sat, Dec 9, 2023 at 9:42?AM Omni < selcor@...> wrote: I have recently acquired a Ten-Tec Centurion model 422 that is in very nice condition, but has a blown up bandswitch and the plate tuning capacitor was arced.? I might be able to salvage the capacitor, but the bandswich will need to be rebuilt or replaced.? If anyone has a switch/parts and/or a capacitor please contact me off list to let me know what you have.
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Re: Potter & Brumfield Sensitive Plate Circuit Relays
Hi ALL,
?
I have amongst my Henry Amps a 3K-A. (My 3K-A was manufactured in 1972 and still works well.)? It has the plate current relay in the B- lead to trip on over current above 1A.
?
?
5.2? ADJUSTMENT OF THE OVERLOAD RELAY
?
A low voltage, variable, metered DC supply of 1 amp is needed for this adjustment. The 3K-A should stay of f during this adjustment.
?
Connect the DC supply to the slider of R103 and to ground and increase the current of the supply to 1 amp.?? RYlOl should trip.?? If the relay does not trip, adjust
Rl03 until the relay trips at about 1 amp. When adjusting the overload relay, reset and check the overload current several times to get an average
setting.? RI03 should be about 3-4ohms.
?
If you download a copy of the 3K-A schematic and manual it explains how the relay works and how to calibrate the trip point.
?
In my opinion it would have been better served as a trip for the grid current.
?
Other amps and devices may have also used this method for protection.
?
?
73
?
Walt
KR4HV
?
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Re: Ten-Tec Centurion Parts Needed
I have a lot of parts for amplifiers and stuff. I handle estates for the local ham club and have? processed estates for several Collins Radio engineers. They collected lots of parts over the years. I don't have any experience with the Centurion, so I don't know what your parts look like. Please send a photo of the switch and specs?for the capacitor - size, value, voltage. Tom KD0HF
On Sat, Dec 9, 2023 at 9:42?AM Omni < selcor@...> wrote: I have recently acquired a Ten-Tec Centurion model 422 that is in very nice condition, but has a blown up bandswitch and the plate tuning capacitor was arced.? I might be able to salvage the capacitor, but the bandswich will need to be rebuilt or replaced.? If anyone has a switch/parts and/or a capacitor please contact me off list to let me know what you have.
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Re: Potter & Brumfield Sensitive Plate Circuit Relays
Thanks Steve. I do not any of the power supply, just the RF deck, but did work it and it pulls in at just under 22vdc
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73 Nick KC0YKO
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Bob
Tom Hess
Nick Jones KC0YKO
Bill K3HZP