[AMRadio] OT Ampeg

DOXEMF at aol.com DOXEMF at aol.com
Sun Apr 8 12:53:39 EDT 2007

 While a bit O.T. for this group, many Hams have roots in tube type guitar amps as players or fixers.
 The late 60's were glory days not only for tubed Ham rigs but also for Guitar amps. The latest tube designs appeared in both of these with the use of the 7591, 6CA7/EL34, 7027, and 6146 for modulator and guitar amp output. Ampeg was a subsidiary of the Magnavox Corp. at that time, and probably due mostly to design copyrights and the availability of a more diverse engineering staff, used the newest tubes in their designs. 
  The Ampeg SVT was probably the highest power tube amplifier made back then amd used a HIFI grade output transformer.
 As Vince said, the full setup with the 300 watt head and two cabinets each loaded with 8 - 10 inch speakers was truly bone shaking.
  The schematic for the SVT can be found online and the amplifier section would certainly make a great modulator using the currently available Russian 6550's.

 One of the Gates BC-5, 5KW transmitters used 4 EL34/6CA7 or KT88/6550 tubes for the audio driver to the CX2500's. The driver transformer itself is the size of a VM-5.
 The driver chassis is a complete stand alone unit that with a VM-5 or eqivalent mounted would be a modulator as is.

 So, watch for those old SVT amps in poor condition and also any remains of the Gates BC-5's. Just add mod tranny and it's soup.


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