813 x 2 -811a transmitter article.

[N4DKD]

I have heard many of the 813 x 811a's on the air. I have yet to find an article on it. I have all the QST'S , some CQ's, most  Radio Handbooks, and most ARRL handbooks. Does anyone know where it originated ?  Just curious .

[Ed-VA3ES]

I have  a rig like that here - a pair of 813's modulated by a pair of 811's.    It's complete, but I haven't tackled restoration yet.      It has at least 5 decks in the rack.  I'd love to get the schematic for it.

Mine was built in the early '50's by VE3ANL, Bud Willing.  I have some  drawings and  diagrams, but nothing substantial.    A  source for this rig would be  very useful.

I've been considering changing out the 811's for 810's (with the comensurate power supply changes).

[WBear2GCR]

Page 169 of the '55 ARRL handbook is one example.

We talked about it last week, fyi: http://amfone.net/Amforum/index.php?topic=24614.0



                 _-_-bear

[N4DKD]

Thanks for the info. I'll check out that thread.

[W3SLK]

Ed said:

I've been considering changing out the 811's for 810's (with the comensurate power supply changes).

That's what I have. Those 813 bottles really shine with the 810's. About 500W out.

[k4kyv]

Another example of the 813 modulated by a pair of 811s is the ART-13. But the stock rig is designed to run a scroteless 100w carrier output. You could do that with a pair of 807's or 1625s modulated by another pair.

[W3RSW]

I guess it was designed to be rugged with little work demanded of the final and mod tubes and with minimal HV problems, insulator flash-over, etc. in high humidity environments.

Wish I hand one after hearing about the neat auto tune features.

[KM1H]

One of my first rigs we built at the local HS was a Meissner EX Signal Shifter driving a 813 with 811 audio. It came out great for a couple of teenagers in the mid 50's. Receiver was a NC-240D and the antenna a 600' long wire going from the 4th floor roof to a tree in the state park behind it. Kind of directional so we mainly worked Europe and Africa on 10-20M during Cycle 19

Carl

[w3jn]

K1JJ's "Tesla 360", pair 813s modulated by a pair of 813s.  Easier to use a single HV supply using all 813s instead of 811s in the mod

http://www.amwindow.org/tech/htm/813/813.htm