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Re: Grid Overcurrent Protection Module?

 

?





On Wednesday, May 28, 2025, 11:58 AM, Steve <k0xp@...> wrote:

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







Re: Grid Overcurrent Protection Module?

 

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Didn't know there was one.... Just asked to join.

Steve, K0XP


On 5/28/2025 9:01 AM, DupyRail via groups.io wrote:
Maybe ask on the Ameritron Amp FB page.

73? Andy? K9ATX



On 5/28/2025 10:58 AM, Steve via groups.io wrote:
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







--
See my QRZ.com page at


Re: Grid Overcurrent Protection Module?

 

Maybe ask on the Ameritron Amp FB page.

73? Andy? K9ATX

On 5/28/2025 10:58 AM, Steve via groups.io wrote:
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




--
"Where the Old Soo crossed the New Soo"
Duplainville, Wisconsin

Broadcastify Train Scanner:

Youtube Channel:


Grid Overcurrent Protection Module?

 

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


Re: 6 Meter Amp WTB

 

Here's a King conversion sb-220 converted to 6 meter already done.
?
?


Re: Wanted: YC-156

 

Contact Jim Klein,? K7RDX.? ? ?He builds loads of? YC-156 amps for folks....and has a source for tubes.? Check out his qrz page.?

Watch out, there are a lot of dud YC-156 /? YC-179 tubes out there.? ? Local buddy bought a total of? 12 x YC-156's...and only 3 of em are good. ( this was 10 yrs ago).? The rest have low emission, and / or develop a grid short after just 5 mins into the 8 min warmup. ( per Reid at Eimac, it needs a 8 min warmup, not a 6 min warmup).? B+ can be applied at the same time as turning on the fil..... provided the tube is biased to cutoff.?

Most tubes these days are pulls of pulls.? ?The 11m ops got a hold of em..then pile drive em, and pulverize em.?

The only way to test em, is to stuff them into an amplifier.?


Re: LK500-ZC Fan Thermal Switch

 

OK I found the answer to question 2.

I rubbed the existing switch clean and was able to decipher some numbers including F140, so I'll go with that.

140¡ãF equates to 60¡ãC, which sounds about right to me.

I'm still looking for LK500-ZC manual.

73, Alek.

On 25/05/2025 12:53 pm, Alek Petkovic via groups.io wrote:
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.





LK500-ZC Fan Thermal Switch

 

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.


Re: 6 Meter Amp WTB

 

I posted a related question (on Clipperton-V) to amps@... reflector in early 2024.

URL below should take you to archive of the (fairly brief) conversation on the unit.



73 Dave WB0GAZ


Wanted: YC-156

 

Hi,
?
Looking for a spare YC-156 with good emission for my HF amp.
Please respond with price, condition, and picture. Send email to
?
Thanks,
?
Jack, WB8BFS
?
?


Re: King Conversions 6m Amp

 

¿ªÔÆÌåÓý

Now there is a good 6m amp.?

Lou's sb-220 conversions make more power on 6m than they did on HF in their original form.

73, Alek VK6APK.

On 22/05/2025 12:38 am, Steve via groups.io wrote:

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:??


King Conversions 6m Amp

 

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:??


Re: 6 Meter Amp WTB

 
Edited

Steve I¡¯m not sure where you¡¯re at. I¡¯ve gone solid state on 6 m. I have a very nice SB 220 it¡¯s converted to six with a variable input so it covers a whole band. But I¡¯m in Idaho.
n7uvh


Re: GS35 2m Amp problems

 

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Dunno what causes it but this is the second instance I have seen. First one was VK6OX's dual GI7B 6m amp built by VK3ZL (SK) and now this GS35B 2m amp.

In Andy's 6m amp, all protection diodes were in place.

Possible or impossible, it happens and I won't die wondering how or why.?

73, Alek.


On 21/05/2025 2:16 am, Jim VE7RF via groups.io wrote:

On Tue, May 20, 2025 at 02:03 AM, Alek Petkovic wrote:

>Like I said, if C1 was moved to the other side, between L2 and the cathode, the fault would not occur. I'm not sure that it would be good RF practice but DC wise, it would solve the problem we both had.

>73, Alek VK6APK


Agreed,? He has the C1 coupling cap in the wrong location.?

I'm not understanding why the C2 variable cap arced ??? ?An anode to grid arc would not cause it...... even with C1 in the wrong location.? ?The fault current path is from grid to chassis....then back to the B-.?
There should be safety diodes wired between chassis...and B- of HV filter caps.?

On his pix of the arced plates on C2,? they don't appear to be centered...... but that may be the angle of the pix.?


Re: GS35 2m Amp problems

 

Picture of W6Po 2 meter amplifier input circuit.

On Tuesday, May 20, 2025 at 02:16:09 PM EDT, Jim VE7RF via groups.io <jim.thom@...> wrote:


On Tue, May 20, 2025 at 02:03 AM, Alek Petkovic wrote:

>Like I said, if C1 was moved to the other side, between L2 and the cathode, the fault would not occur. I'm not sure that it would be good RF practice but DC wise, it would solve the problem we both had.

>73, Alek VK6APK


Agreed,? He has the C1 coupling cap in the wrong location.?

I'm not understanding why the C2 variable cap arced ??? ?An anode to grid arc would not cause it...... even with C1 in the wrong location.? ?The fault current path is from grid to chassis....then back to the B-.?
There should be safety diodes wired between chassis...and B- of HV filter caps.?

On his pix of the arced plates on C2,? they don't appear to be centered...... but that may be the angle of the pix.?


Re: GS35 2m Amp problems

 

The W6PO amplifier which many have been built has the coupling cap the first component after the input connector. I built many of these and never had an issue. I believe this to be a close copy? It looks like the cap may have had issues when the amp was built??

On Tuesday, May 20, 2025 at 02:16:09 PM EDT, Jim VE7RF via groups.io <jim.thom@...> wrote:


On Tue, May 20, 2025 at 02:03 AM, Alek Petkovic wrote:

>Like I said, if C1 was moved to the other side, between L2 and the cathode, the fault would not occur. I'm not sure that it would be good RF practice but DC wise, it would solve the problem we both had.

>73, Alek VK6APK


Agreed,? He has the C1 coupling cap in the wrong location.?

I'm not understanding why the C2 variable cap arced ??? ?An anode to grid arc would not cause it...... even with C1 in the wrong location.? ?The fault current path is from grid to chassis....then back to the B-.?
There should be safety diodes wired between chassis...and B- of HV filter caps.?

On his pix of the arced plates on C2,? they don't appear to be centered...... but that may be the angle of the pix.?


Re: GS35 2m Amp problems

 

On Tue, May 20, 2025 at 02:03 AM, Alek Petkovic wrote:

>Like I said, if C1 was moved to the other side, between L2 and the cathode, the fault would not occur. I'm not sure that it would be good RF practice but DC wise, it would solve the problem we both had.

>73, Alek VK6APK


Agreed,? He has the C1 coupling cap in the wrong location.?

I'm not understanding why the C2 variable cap arced ??? ?An anode to grid arc would not cause it...... even with C1 in the wrong location.? ?The fault current path is from grid to chassis....then back to the B-.?
There should be safety diodes wired between chassis...and B- of HV filter caps.?

On his pix of the arced plates on C2,? they don't appear to be centered...... but that may be the angle of the pix.?


Re: Hi from the newbie.

 

Thanks for the replies.? I get the feeling this will be a long adventure.


Re: 6 Meter Amp WTB

 

With a little checking it looks like Dentron sold a conversion kit to do that. Not that it matters because you will never find the kit.

On Saturday, May 17, 2025 at 04:53:55 PM EDT, Steve <k0xp@...> wrote:


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







Re: 6 Meter Amp WTB

 

I seem to remember an article on this. Not sure if it was 2 to 6 or 6 to 2? I have one person to check with. Mike

On Tuesday, May 20, 2025 at 09:00:32 AM EDT, David Feldman via groups.io <wb0gaz@...> wrote:


Steve - I have a Clipperton V in Colorado (Denver area) - I had investigated (very briefly) converting to 6M, and the response was roughly "yes, it can be done, no I don't have the information on how." As I recall the power transformer is slightly different than the Dentron amplifiers of a similar form-factor (slightly lower plate voltage but I believe same total power capability - - better suited to the 4CX250 series plate voltage requirement), however, it did look reasonably promising project.

Should you proceed down that path and/or be interested in a second Clipperton V (given that you are somewhere in the? southwest US!) please feel free top me a line; if you don't wish the second amplifier but do continue down the 6M conversion path, I'd be interested in following your project effort.

73 Dave WB0GAZ