[Amps] Multi tube amp

[Fuqua, Bill L]

  I have not seen anything close. If I recall it used a airdux coil as an auto transformer to match the output.

A am sure it used sweep tubes and voltage multiplier straight off the power line.

73

Bill wa4lav



________________________________
From: Amps <amps-bounces at contesting.com> on behalf of Jim Thomson <jim.thom at telus.net>
Sent: Wednesday, December 6, 2017 1:26 PM
To: amps at contesting.com
Subject: [Amps] Multi tube amp

Date: Wed, 6 Dec 2017 07:42:40 -0600
From: "Roy Koeppe" <royanjoy at ncn.net>
To: <amps at contesting.com>
Subject: Re: [Amps] Multi tube amp

<Seems to me there was also one in strays that use something like a dozen 1625?s on parallel...(etc.)?

<Yes that was my amp ? think it had 20 of them with a broad banded input and output. I can?t locate the issue so far! Had a photo of it in Strays. I used that amp for several years.

<73,   Roy    K6XK   Iowa

##  saw that in an old qst.  The plate load Z was so low, it was  75 ohms.... no description on how u get rid of harmonics !   Me,  I woulda used a plate block cap, and no more,,, then stuff it
into the ant.

##  On that galaxy  2000 amp, it used 10  x 6HF5 sweep tubes..and was a 80-10m affair.    1 kv  at 2A  to provide the  2 kw input..and  1.2 kw output at the time.
Plate load Z  was less than  290 ohms.   That would of course require VERY high values of tune and load C.....and a real small coil.   Plus aprx  a whopping 20A
of circulating RF current through the coil +  bandswitch.      Their fix was unique, they used a simple step up  Z transformation.    Stepped the plate load Z up high enough,
such that... normal values  of PI net could be used.   Enter a plate load Z of 290 ohms into the GM3SEK  Pi  spreadsheet, and u will see the crazy high values required for
  both  air variables...and the tiny values used for the coil.   The PI-L  is no better.

Jim   VE7RF

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