[ARC5] BC-AO-430 transmitter

[J Mcvey]

It would seem to me that a series filament "cathode"  circuit  is different than a series heater circuit.Series heaters as in the ARC-5 radios will make no difference in the circuit operation since the cathode is isolated from the heater.
In these old types, the series filament IS the cathode so current from one stage will flow into the other, providing a sort of negative feedback?There are no bypass caps on the series connection to prevent this.
With the cathode types , the heater is now just resistor being introduced between the stages . 
I would suppose that wiring the the cathode to the ground side makes sense and the "floating cathode" would be connected to the center connection.
Alternatively, maybe try a "no feed back" scenario by putting the cathode connection on the "hot side of the filament and using a large ceramic bypass cap to ground where the filament power enters at the first tube in the chain. ( especially in the RF section).
Just some random thoughts to consider...

   On Sunday, November 14, 2021, 12:05:12 AM EST, Steve WD8DAS via ARC5 <arc5 at mailman.qth.net> wrote:  
 
 
 Ben, I will order some of your adapter kits in a separate email.
Dave, is it possible to search the list archives for the past discussions of this topic?  I'd like to see the suggested connections of 5763s in place of the tubes in the BC-AO-430.  

Here are my thoughts so far...
Triode connection
4-pin Tube        6AQ5     5763   
Plate 2           5 & 6    1 & 6
Grid 3            1 & 7    8 & 9
Cathode 1 & 4     2        1 & 3    
                    3/4    4/5    Heaters

 I've not puzzled out how to interconnect the cathode and heaters yet...

 
Steve WD8DAS

http://www.wd8das.net/http://af4k-crystals.com
--------------------------------------------------------------------
Radio is your best entertainment value.
--------------------------------------------------------------------



______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: https://www.qsl.net/donate.html  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20211114/2147f232/attachment-0001.html>