Well, I picked up the amp and it looks pretty much complete minus the tubes and vacuum variable which I have already found one.?
I was looking at some of the Russian tubes and found that they have a 3CX300A1 with the same pin configuration that I can get for around 80 plus shipping. Just need to look at the specs closer and run the numbers.
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Re: Need Help with Amp Supply LK500ZC
Just letting you know,?
Effective? Nov 2024 ECONCO no longer tests tubes at no charge.
The fee is now $150 per tube.
thanks to the new corporate owner TransDigm.
?
Reid??
?
Re: Need Help with Amp Supply LK500ZC
? Date: Wed, 01 Jan 2025 11:27:50 PST
?
I believe Econco will function test transmitting tubes.
You might check with W8JI, too.
?
Hal Mandel
W4HBM
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Re: Need Help with Amp Supply LK500ZC
That helps,? I was thinking maybe he meant the plate choke.
Thanks
On Thu, Jan 2, 2025, 11:46?AM mike repinski via <mikflathead= [email protected]> wrote:
Plate Blocker is the big capacitor that is connected to the plate tune capacitor coming off the tube anode. Should be 5kv or more rated. Shorts won't always show with a multi meter till they get warm.
On Thursday, January 2, 2025 at 11:44:33 AM EST, John Roland via <johnroland51= [email protected]> wrote:
[Edited Message Follows]
Hal and all,
I've started testing each tube in each socket individually and will post my results hopefully later today.? The first tube doesn't show any shorts with a DMM.? I don't know what a "plate blocker" is.? Thanks for the help.?? /John
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Re: Need Help with Amp Supply LK500ZC
Plate Blocker is the big capacitor that is connected to the plate tune capacitor coming off the tube anode. Should be 5kv or more rated. Shorts won't always show with a multi meter till they get warm.
[Edited Message Follows]
Hal and all,
I've started testing each tube in each socket individually and will post my results hopefully later today.? The first tube doesn't show any shorts with a DMM.? I don't know what a "plate blocker" is.? Thanks for the help.?? /John
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Re: GG Amplifiers Bias Cut Off
Hey Alek, How's 20 meters been down in your neck of the woods lately? Maybe we can get on and say hi again one of these days soon along with your "Jack Daniels" friend! 73 and happy new year, Bob W4JFA?
Yes, that's good Alan.
Whenever I get an amplifier in that is wired the "wrong" way, I
always make the simple change.
73, Alek.
On 2/01/2025 7:45 am, Alan - W5ARM via
wrote:
I have four Henry amplifiers (2-KD-Classic, 2KD-5, 3K-A, and
3K-Classic-8877), and all of them have the resistor
always-in-circuit, with the relay acting as a bypass. Likewise,
my Drake L-4B , with the "Soft-key/Soft-start/Bias board"
installed, also has the relay configured to bypass the
always-in-circuit resistor.
?
So, on some (many) amplifiers, the designers did get it
right.
?
--
73,
~Alan
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Re: Need Help with Amp Supply LK500ZC
Hal and all,
I've started testing each tube in each socket individually and will post my results hopefully later today.? The first tube doesn't show any shorts with a DMM.? I don't know what a "plate blocker" is.? Thanks for the help.?? /John
|
Re: GG Amplifiers Bias Cut Off
Yes, that's good Alan.
Whenever I get an amplifier in that is wired the "wrong" way, I
always make the simple change.
73, Alek.
On 2/01/2025 7:45 am, Alan - W5ARM via
groups.io wrote:
toggle quoted message
Show quoted text
I have four Henry amplifiers (2-KD-Classic, 2KD-5, 3K-A, and
3K-Classic-8877), and all of them have the resistor
always-in-circuit, with the relay acting as a bypass. Likewise,
my Drake L-4B , with the "Soft-key/Soft-start/Bias board"
installed, also has the relay configured to bypass the
always-in-circuit resistor.
?
So, on some (many) amplifiers, the designers did get it
right.
?
--
73,
~Alan
|
|
|
Re: GG Amplifiers Bias Cut Off
I have four Henry amplifiers (2-KD-Classic, 2KD-5, 3K-A, and 3K-Classic-8877), and all of them have the resistor always-in-circuit, with the relay acting as a bypass. Likewise, my Drake L-4B , with the "Soft-key/Soft-start/Bias board" installed, also has the relay configured to bypass the always-in-circuit resistor.
?
So, on some (many) amplifiers, the designers did get it right.
?
--
73,
~Alan
|
Re: Need Help with Amp Supply LK500ZC
John,
?
It could be a cold solder joint in a tube pin.
?
If it was an interelectrode short, you could use a DMM
to explore.
?
If it was a defective plate blocker it would
show up with a meter, out of the circuit.
?
You can run 1 tube at a time, no problem,
and do each separately from each socket.
?
If there was a bypass cap short this might also
be seen, as the bypass circuit will mess up on
both tubes at the same time, but only on one socket
at a time. Again, use a DMM to trace.
?
When you run 1 tube at a time, note the ammeter
readings at 1 watt, 5 watts, 10 watts, etc., and
compare.
?
Hal W4HBM
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Drake L4/L7 power supply upgrade board for sale
Happy New Year,
?
I have a fully assembled, tested, but never used Heathkit Shop power supply upgrade board for Drake amps for sale. Price is $125.00 plus shipping from 23418. Details and pictures are available on request.
?
73,
Garry - K4OR
k4or@...
|
Re: Need Help with Amp Supply LK500ZC
I believe Econco will function test transmitting tubes.
You might check with W8JI, too.
?
Hal Mandel
W4HBM
|
Re: Need Help with Amp Supply LK500ZC
Happy New Years Everyone,
?
Its that time of year when I'm spending more time in the shack and am back looking at the LK-500 ZC.? In response to the many (much appreciated ) suggestions that I could deal with, I replaced the two little blue relays: one bypasses the cut-off resistor, and the other energizes the antenna relays.?? Unfortunately, this changed nothing.?
I also put a request on three of my regional (Portland, Columbia River Gorge and Bellingham) ARC reflectors looking for someone willing to test my tubes in their amplifier and the only replies I got was from people candidly saying they wouldn't take a chance on damaging their amps with my dubious tubes.?
?
I'm thinking if there is a tube defect, it seems unlikely both tubes would be defective.?? Could I test that by removing each tube and seeing if the overheating results when each tube is operated individually?? And would running a single tube risk further damage to the? amplifier?
?
To refresh your memory of this issue, the amp will (usually) idle with no issues, but when more than 10 watts of exciter power is applied, both tubes begin to glow red. The front tube seems to lead the rear tube.
?
Thanks /John W7SWB
?
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Re: Wanted: 6m low power linear amp
That's a good suggestion Mike, thanks, I'll look into it.
|
Re: Wanted: 6m low power linear amp
Maybe locate the power amplifier from a Yaesu FT-736 6 meter module. The 736 parts have gotten cheap.
I'd like to acquire a 10 - 50 watt linear power amp to use with a 50 MHz. beacon transmitter. Input must be in the 10-18dBm range. Kit or assembled or "needs repair" is fine.?
Suggestions?
Thanks,
Robin K4IDC?
|
Wanted: 6m low power linear amp
I'd like to acquire a 10 - 50 watt linear power amp to use with a 50 MHz. beacon transmitter. Input must be in the 10-18dBm range. Kit or assembled or "needs repair" is fine.?
Suggestions?
Thanks,
Robin K4IDC?
|
Re: AL-80B Transformer Solution now that Ameritron is closing?
Looking in the MFJ catalog, it looks like the xmfr ( part
@406-1109-2C ) has the following ratings:
Secondary:
1047 vac? 0.1Adc
22 vac? 1.5Adc? CT
5.2Vac? 15Adc? CT
Primary:? 90 - 140?? 205 - 250? w/buck-boost winding
Hope this helps.? 73? Andy? K9ATX?
On 12/31/2024 3:55 PM, Alek Petkovic
via groups.io wrote:
Snap!
Yes, it is a specifically designed transformer and I'm sure Tom
will have the correct information on it.
73 from sunny Western Australia where we have made it into
2025.
Alek VK6APK.
On 31/12/2024 9:23 pm, Louis
Parascondola via groups.io wrote:
Contact Tom W8JI, he will know for sure! ?He¡¯s the only guy I
would rely on for exact data concerning that transfomer. ?Lou
On
Tuesday, December 31, 2024, 1:59 AM, Warren Holcomb (WR0S) via
groups.io <wr0s@...>
wrote:
I have a transformer company that might be able to
assist.? Does anyone know the exact spec of the Ameritron
AL-80B power transformer?? ?I'm assuming secondaries are?
9VAC @ 1.5A,? ?3.53VAC @ 15A, and 1100VAC @ .6A? ?I have
dug through the manuals and can't find anything specific.?
You can see the voltage doubler in the schematic though.?
And if 3100 No load volts is the DC target for B+??
?Thanks!? ?Warren? (WR0S)
--
"Where the Old Soo crossed the New Soo"
Duplainville, Wisconsin
Broadcastify Train Scanner:
Youtube Channel:
|
Re: AL-80B Transformer Solution now that Ameritron is closing?
Snap!
Yes, it is a specifically designed transformer and I'm sure Tom
will have the correct information on it.
73 from sunny Western Australia where we have made it into 2025.
Alek VK6APK.
On 31/12/2024 9:23 pm, Louis
Parascondola via groups.io wrote:
toggle quoted message
Show quoted text
Contact Tom W8JI, he will know for sure! ?He¡¯s the only guy I
would rely on for exact data concerning that transfomer. ?Lou
On
Tuesday, December 31, 2024, 1:59 AM, Warren Holcomb (WR0S) via
groups.io <wr0s@...> wrote:
I have a transformer company that might be able to
assist.? Does anyone know the exact spec of the Ameritron
AL-80B power transformer?? ?I'm assuming secondaries are?
9VAC @ 1.5A,? ?3.53VAC @ 15A, and 1100VAC @ .6A? ?I have dug
through the manuals and can't find anything specific.? You
can see the voltage doubler in the schematic though.? And if
3100 No load volts is the DC target for B+?? ?Thanks!?
?Warren? (WR0S)
|
Re: AL-80B Transformer Solution now that Ameritron is closing?
Contact Tom W8JI, he will know for sure! ?He¡¯s the only guy I would rely on for exact data concerning that transfomer. ?Lou
On Tuesday, December 31, 2024, 1:59 AM, Warren Holcomb (WR0S) via groups.io <wr0s@...> wrote: I have a transformer company that might be able to assist.? Does anyone know the exact spec of the Ameritron AL-80B power transformer?? ?I'm assuming secondaries are? 9VAC @ 1.5A,? ?3.53VAC @ 15A, and 1100VAC @ .6A? ?I have dug through the manuals and can't find anything specific.? You can see the voltage doubler in the schematic though.? And if 3100 No load volts is the DC target for B+?? ?Thanks!? ?Warren? (WR0S)
|
Re: AL-80B Transformer Solution now that Ameritron is closing?
Would Ameritron forward there suppliers info?
I have a transformer company that might be able to assist.? Does anyone know the exact spec of the Ameritron AL-80B power transformer?? ?I'm assuming secondaries are? 9VAC @ 1.5A,? ?3.53VAC @ 15A, and 1100VAC @ .6A? ?I have dug through the manuals and can't find anything specific.? You can see the voltage doubler in the schematic though.? And if 3100 No load volts is the DC target for B+?? ?Thanks!? ?Warren? (WR0S)
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Brandon DX
Bob
Alan - W5ARM
HaL Mandel
Robin Midgett