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Re: [Amps] Big HV Supply

To: "Carl" <>, <>
Subject: Re: [Amps] Big HV Supply
From: "Jim Thomson" <>
Date: Wed, 8 Aug 2018 08:52:44 -0700
List-post: <>

-----Original Message----- From: Carl
Sent: Wednesday, August 8, 2018 7:44 AM
To: Jim Thomson ;
Subject: Re: [Amps] Big HV Supply

<The LK-550 runs three 3-500's and cooling would likely limit power as it is
a fan. Ive had them up to 2200W or so with 150W drive....nothing to brag
about tho!

Ive built several LK-800's for 6M EME that do a solid 5 out without
complaining and going to a good EBM fan.

On HF I dont know how well the bandswitch will hold up over time and the
fixec C used needs beefing up.

Another thing I dont know is tube life at that power but money isnt
important to some.

BTW what is a full output YC-156 going for these days? It came from Tom,
WD8??? ages ago. Also have a filament xfmr and one of those UK sockets all
set up for good air flow. I'll never get around to building another amp and
dont need QRO here.


## YC-156 does not use a socket. Its got a grid flange that just bolts to chassis. Then the fil lugs below. Indirectly heated like a 8877. Eimac sez 6 min warm up minimum, but Reid Brandon and I talked about that years ago, and he highly recommended a full 8 mins. Typ they go for $400.00 for a good one. I dont recommend it these days as they are real scarce... and are just pulls of pulls. The 11m ops have beaten the crap out of them too. I designed a YC-156 80-10m for a local buddy, and he bought a total of 12 tubes, TWELVE, and only 3 are any good. What typ happens is you end up with a grid to fil short, or grid to cathode short after just 5 mins..with fil on, blower on, and NO B+. Without at least 2-3 known good tubes, I would not build a YC-156 from scratch. Loads of YC-156 amps out there, so should be easy to sell, with the provisio that the tube functions in a working amp. Buddy bought every YC-156 he could
get his hands on...and 9 were duds.   One good one, and  2 x semi good ones.

## That OM power OM-4000 HF sells for $6K..and does an easy 4-5 kw out all day long. It comes with a FCC approved input board, which has the input attenuators built onto it, so it needs like 60+ watts to drive it to 1.5 kw. The attenuator is easily bypassed, then it can easily be driven to 4 kw out with just 20 watts..and more with a bit more drive. Also comes in both a manual..and full auto version..and both use a pair of chinese FU-728F tubes. They also make a remote small console to remote the amp, if u want, cheap, like $288.00 Emtron, when they were in business, also made a similar amp, same pair of chinese tubes, and they rated
their version at 4.5 kw out.

## JA6TAY, from bear-el now has a separate company that mass produces his 160-10m, 3CX-3000A7 commercial amp. 5++ kw out with just 200 watts of drive. Looks sorta like a Henry radio 8K ultra.. but actually built correctly. RF deck + B+ supply etc, sit in a 100 kg box..complete with 7.5 kva CCS xfmr. Small box in shack contains the myriad of pre-sets, and fine adjustment tune control etc, + 5 x panel meters. 2nd item down. I have all the schematics for it. Uses a motor driven vac tune cap..and a motor driven 10 kw rated roller coil, then a myriad of vac relays to switch in various combo's of fixed load caps. He ships a helluva lot of em.

## which UK socket do you have ? There is some outfit in the UK I believe that makes quality SK-1320 sockets for the bigger GG triodes...... at a relatively cheap price... like 188 Euro's... like $230 US funds. On a related note, if the grid driven version of the socket is used... which is called a SK-1300..and u try to modify it for GG, it can be done, BUT, in addition to 4 x cu straps being installed, on edge, so not to impede airflow, the 4 x small ceramic insulators on the socket assy also have to be removed..and replaced with aluminum threaded cylinders. If the al cylinders are not installed, all hell breaks loose, and a parasitic will result. With the 4 x al cylinders and 4 x straps, its rock solid..and no suppressor required on the series of GG triode tubes that use the SK-1320 socket. cheap source for solid AL spacers with a hole down the center,,, or a threaded hole. U can get virtually any OD + ID and any thread size..and also overall length. Saves a lot of screwing about fabricating
them by hand.

Sri for the diatribe, but thats this weeks bits of latest info that I know of. Only other recent news is the availability of the teflon version of LMR-600. A buddy found a source, they typ come in 17 ft lengths with type N connectors. The Type Ns are tossed, and replaced with 7-16 din or .875 EIA flange connectors. Typ used for rotor loops

Jim   VE7RF

----- Original Message ----- From: "Jim Thomson" <>
To: <>
Sent: Monday, August 06, 2018 12:29 PM
Subject: [Amps] Big HV Supply

Date: Sun, 5 Aug 2018 15:46:55 -0400
From: "Carl" <>
To: "John Keating" <>, "Jim"
<>, "'Herbert Schoenbohm'"
<>, "'Amps group'" <>
Subject: Re: [Amps] Big HV Supply

<All the big Amp Supply transformers were Dahl, some had a tapped HV winding
<for the LK-550 and LK-800 and others were custom non advertised for the
<3CPX800A7 LK-800

<You would be surprised at how many went to 160M "big guns". There is little
<honor on that band any longer.


## How much power can u get out of a LK-550 or LK-800..with a big xfmr ?
I dont even know what tube  or how many many tubes were in those amps.

What are we talking abt here, like 3 x 3cpx800a7s putting out 3.5 kw or what ? I wouldnt get wound up abt a lousy 3 – 4db esp on 160m band. IMO, they should increase the limit on 160m. Thats one band where some extra.. oomph would work, esp with sky high noise levels. Noise level with typ ssb rx filter band widths typ results
in high noise levels... making life a bitch on 160m  ssb.

Jim   VE7RF

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