There is an interesting quality about using the 6AQ5 tube, since it normally
is not used in receivers - except for audio output. Like the Mosley
receiver, only one tube is needed to be able to replace any bady tube. The
6AQ5 is somewhat unusual, however, in that it connects pin 1 and 7 together,
so there are few drop in replacement tubes.

The 6BM5 would be a drop in replacement with more gain. One other tube
should work as a drop in replacement - the 6BE6. Instead of pin 1 and 7
being connected, they go to separate control grids. Have not tried it, but
I think it will work.

6AQ5 tubes are still plentiful and cheap and it gives you something to talk
about if you get tired of talking about the weather. Here in NW Oregon, we
just say rain and then move on to something else.

Colin K7FM

On 1/20/06 10:07 PM, in article
, "COLIN LAMB"
wrote:

There is an interesting quality about using the 6AQ5 tube, since it normally
is not used in receivers - except for audio output. Like the Mosley
receiver, only one tube is needed to be able to replace any bady tube. The
6AQ5 is somewhat unusual, however, in that it connects pin 1 and 7 together,
so there are few drop in replacement tubes.

The 6BM5 would be a drop in replacement with more gain. One other tube
should work as a drop in replacement - the 6BE6. Instead of pin 1 and 7
being connected, they go to separate control grids. Have not tried it, but
I think it will work.

6AQ5 tubes are still plentiful and cheap and it gives you something to talk
about if you get tired of talking about the weather. Here in NW Oregon, we
just say rain and then move on to something else.

Colin K7FM



Being across the Big Muddy from you, I can relate to the rain comment.

I like the 6BE6 for lots of things. I used it once to add a product
detector to my 75A2 many years ago, by replacing a 6BA6 with it and then
doing some very minor rewiring.

Don

Ya know,
I remember the original article in QST about this 6AQ5 regen set. I
still have the magazines but can't remember the exact year.

I recall in the first paragraph, the author stated that, "some eyebrows
may be raised at using a beam audio tube for a detector". And as I
recall, he explained why. He just tried a number of different tubes for
smoothness of operation, and the 6AQ5 won.

I built my first two tube blooper in 1954 and used a 6J7G regen
detector and a 6C5GT one step AF amplifier driving a pair of Trimm 2000
ohm headphones.

It worked great and covered 80 and 40 meters.

John