[Amps] 4 x 807

[Bill L. Fuqua]

No one is picking on you. Us old guys were always looking for a way to build cheap stuff. This was an unusual approach. If you did not want to modify the 1625's you could use 837 tubes instead (change filament voltage or wire the filaments in pairs in series). 
   I took a more extreme approach. I paralleled 4x  6AG7 pentodes and mounted them into a heat sink make from a large block of aluminum. After conditioning them by Bringing up voltage slowly letting them arc over and then starting over again until I got to a full 1200 volts, I could drive them with a couple of watts SSB or CW and  got a plate input of around 300 watts. Don't know what the output was then but made plenty of contact with the amp on 20 meters. I still have parts of the amp laying around and have thought of doing it again and making some measurements. Heck, I was only 19 then anyway.
	The power supply was made of a TV transformer with a voltage doubler using some AC motor running capacitors from air conditioners I found in a pile on the side of a country road. I wound my plate choke on a tall ceramic insulator.
	At one time I took tube apart to find that unlike some metal tubes these did not have a glass envelope inside the metal shield but a glass seal at the bottom. If it were not for the plates being in the way it could have been a good external anode power tube. 

73
Bill wa4lav

-----Original Message-----
From: "Svante Nordenstrom" <sm3dyu at ji-net.com>
To: <Amps at contesting.com>
Date: Sun, 15 Jun 2003 12:08:59 +0700
Subject: [Amps] 4 x 807

Apparently it was not the final comment. Glad that I did show my lack of knowledge here, so we all could learn, as this was completely new to me. Thanks for the corrections.

73
Sam  HS0ZDY
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in a pile on the side of a country road. I wound my plate choke on a tall ceramic insulator.
	At one time I took tube apart to find that unlike some metal tubes these did not have a glass envelope inside the metal shield but a glass seal at the bottom. If it were not for the plates being in the way it could have been a good external anode power tube. 

73
Bill wa4lav

-----Original Message-----
From: "Svante Nordenstrom" <sm3dyu at ji-net.com>
To: <Amps at contesting.com>
Date: Sun, 15 Jun 2003 12:08:59 +0700
Subject: [Amps] 4 x 807

Apparently it was not the final comment. Glad that I did show my lack of knowledge here, so we all could learn, as this was completely new to me. Thanks for the corrections.

73
Sam  HS0ZDY
_______________________________________________
Amps mailing list
Amps at contesting.com
http://lists.contesting.com/mailman/listinfo/amps