[Amps] [ham_amplifiers] RE: 3CX1500A7/8877 vs el cheapo GS-35B

[Carl]

I doubt if any respectable amp company will get bit by Russian surplus again. It may be a great ham tube but unless there is current production its a loser for an OEM.

I could care less what country a tube comes from. If its reliable and cost effective its a choice.


Carl
KM1H



Carl
KM1H


  ----- Original Message ----- 
  From: Leigh Turner 
  To: amps at contesting.com 
  Cc: ham_amplifiers at yahoogroups.com 
  Sent: Monday, July 30, 2012 6:56 AM
  Subject: [ham_amplifiers] RE: [Amps] 3CX1500A7/8877 vs el cheapo GS-35B


    

  Good comments here Bob; you've nailed some relevant points here.

  The GS35B does indeed need a higher plate voltage / plate load impedance to
  achieve parity in efficiency with the 8877; complaining about achieving
  circa "only" 55% efficiency and a few extra watts of exciter drive is
  splitting hairs; particularly in a GG AB2 SSB linear.

  At circa $120 the NOS GS-35B represents the best bang for buck in the 1500W
  plate dissipation triode tube class; costing a meagre 10% of that of a new
  8877 from CPI/Eimac, or 15% of the cost of an excellent Chinese clone. 

  Most affordable key RF components for building QRO amps like tubes, vacuum
  capacitors, vacuum relays, doorknob capacitors, roller inductors, etc are
  all made by non-USA countries. If it weren't for the China tube companies
  producing affordable clones of the popular ham-radio tubes and Russian NOS
  surplus parts, then readily available tube amplifier components would be a
  thing of the past...or the exclusive domain of the wealthy ham.

  Cheers,

  Leigh
  VK5KLT 

  -----Original Message-----
  From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
  Behalf Of Robert Briggs
  Sent: Monday, 30 July 2012 5:11 PM
  To: amps at contesting.com
  Subject: [Amps] 3CX1500A&/8877

  Interesting comments re the two types of tubes 8877/GS-35B...I have 
  built six amplifiers using the GS-35B four on 160 meters and two on 6 
  meters...I have found that to make the 35B reasonably efficient you need 
  at least 3500 volts under load...

  I live in VK and we don't have the opportunities to buy 8877 
  pulls...When one considers cost then the GS-35B is way ahead at 
  $120..The efficiency at 3500 volts is around 55%....You must use a tuned 
  input to get the best from the tube..Who cares if you need a few more 
  watts to drive the 35B....Pretty well all transceivers these days have 100 
  or 200 watts output..

  There always seems to be a bias on here by some people regarding 
  anything that isn't made in the US...Hams are generally looking for the 
  cheapest way to build amplifiers and other gear and there is a ready 
  market out there of excellent quality components made in other countries 
  other than the US...

  I spend much of my time custom building amplifiers for VK hams and a 
  large majority of the components come from suppliers like Dr Alex Gavva 
  UR4LL...I have never had a faulty tube or capacitor from that source...

  Bob..VK3ZL..
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