[ARC5] Drift in BC-453

[Kenneth G. Gordon]

On 13 Dec 2017 at 16:16, Robert  Eleazer wrote:

> I think the simplest approach would be to take a spare 85 KHZ BC-453 IF transformer and use it 
> to build a solid state BFO.  The first successful oscillator I ever built used a big old Miller 455 
> KHZ IF transformer and a bipolar transistor.  Use of an FET should enable an even better BFO.
>
> Add the BFO to an R-11A receiver, which I think has rather better construction standards than 
> the WWII vintage sets.

Yes. I agree. The can-caps are sealed with ceramic for one thing.

However, NIB 85kHz BFO cans are still available from Fair Radio Sales, but you have to 
ask for them. One of those would fit better than an IF can in the R-11A. You would have to 
remove one can-capacitor and replace it with metalized-film jobs.

An FET would fit inside the 85 kHz BFO can too.

Also, since the tuning capacitor in the R-11A is identical with the ones in the R-23 or 
BC-453, one could replace the original one, and have a dial.
  
Ken W7EKB


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