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Re: Henry 8K Ultra...
Yeah Jim Because they are always responding to Customer Complaints of which there is no shortage. I owned a 3K-A which had the 3-500Zs Grids sitting above RF Ground. This, among other things, lead me to conclude the HENRY does everything backwards just for sake to they did it their way. Bob AA6XE? On Fri, May 30, 2025, 2:45?PM Jim VE7RF via <jim.thom=[email protected]> wrote:
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Henry 8K Ultra...
A friend has an 8K Ultra he's no longer using and has put my name on it. There's no doubt of its cool factor, but how is the overall design and execution? My local amp guy has his reservations about Henry's designs. Another friend (N6CA) completely converted a 2006 and even removed the Henry name from the faceplate, he was so disappointed in their design (that amp is for sale BTW, which includes Chip's 6M internal preamp).
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I'm asking specifically about the 8K, thanks.
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Dino - KX6D |
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12 KW CCS ON 160-15M....USING THE 3CX-6000A7..... PART 27
Here the air cooled? 50 ohm, 1100 watt glitch resistor assy is installed.? ?Consists of 4 x 50 ohm, type SP globars.....wired in series - parallel.? These are the glass bodied types, designed for oil immersion.... made for dummy loads.? ?For this application, air cooling is ample.? The cooling air is from the intake (filtered) air that feeds the intake of the EBM-Papst? 330 cfm? @ .9" blower.? The open space in the middle of the chassis is where the blower will hang down from the? RF deck above this power supply. (both in the same cabinet).? ? The air being sucked into the blower 1st has to pass by the entire power supply assy as seen here, including the 50 ohm glitch assy. Each resistor? is 1"? diameter x 12" long.? Ceramic standoffs used plus? 1/4" thick Teflon mounting plates. In normal operation, with a 2.5 amp? DC plate current load, for CCS data modes, total? diss in the glitch assy is 312.5 watts? or 78.125 watts? per resistor.? ?Using processed SSB,? average plate current is just 1.25 amps, and total glitch assy dissipation is? 78.125 watts or just 19.53 watts? per resistor. Each resistor is rated for 275 watts CCS in free air, BUT this is at a very high temp, 350 deg C (662 deg F). Each resistor is rated for 3200 joules / 10 kv... or 12,800 joules in total.? ?Energy stored in the 20 x 2500uf lytics is? 3515 joules.? This is with 7.5 kv no load.? ?1 joule = 1 watt second. The filtered B+ is 1st fed to the BUSS? HVU-3? HV fuse..... then to the 50 ohm glitch assy.....then off to the RF? deck.? ?With any B+ to chassis / grnd arc, or say an anode to grid arc, the fault current is 7500v / 50 ohms = 150 amps.? ? 150 amps will open off the 3 amp rated? HVU-3? fuse in 1 msec (tested).? ?The 50 ohm glitch assy LIMITS the fault current to a safe value.... while the HV fuse INTRERUPTS the fault current....... event over.? |
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Meter for Henry 2 K HF Amp
I know this is a long shot, but it is worth
trying. I have a Henry 2 K HF amplifier that I am trying to repair. It is a plain Henry 2 K --- no suffix after the K. It has the "tear drop" type meters on it. The "multimeter" (the one on the left) no longer functions, so I am looking for a replacement. It appears to have a 1 ma movement. Yes, I am certain it is the actual meter, as I can put my DMM in its place, and it works OK. Any possibility that someone has a donor unit with a good meter? Or any help on where to find one? All help is appreciated. Thanks. 73, Ken, W8EK Ken Simpson E-mail to W8EK@... or W8EK@... Voice Phone (352) 732-8400 . |
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Re: Grid Overcurrent Protection Module?
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On Wednesday, May 28, 2025, 11:58 AM, Steve <k0xp@...> wrote:
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Re: Grid Overcurrent Protection Module?
¿ªÔÆÌåÓýDidn'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. --
See my QRZ.com page at |
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Re: Grid Overcurrent Protection Module?
Maybe ask on the Ameritron Amp FB page.
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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. --
"Where the Old Soo crossed the New Soo" Duplainville, Wisconsin Broadcastify Train Scanner: Youtube Channel: |
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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 |
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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.? |
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Re: LK500-ZC Fan Thermal Switch
OK I found the answer to question 2.
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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. |
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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. |
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Re: King Conversions 6m Amp
¿ªÔÆÌåÓýNow 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:
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King Conversions 6m Amp
Yes I am one of those guys who has bought an amp and never used it.
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Have a King Conversions 6m Amp built on a SB-220 that has not been run since Lou W1QJ built it for me.
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By the time the amp was done I had an solid state amp that covered 6m, so it never has been used.
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$1000 plus shipping from 54220? (two boxes - tubes will ship separate)
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73 Steve K9ZW Blog:?? |
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Re: GS35 2m Amp problems
¿ªÔÆÌåÓýDunno 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:
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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:
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.? |
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