[Collins] 51J4 problem

[Dr. Gerald N. Johnson]

On Mon, 2007-08-13 at 13:14 -0400, jeremy-ca wrote:
> My virgin J4 died today on band 1 (BC band) but is fine on all other 
> segments. Besides a tube or crystal is there anything else specific to this 
> model?
> 
> Anyone have a spare crystal if needed?
> 
> Carl
> KM1H
> 
There's an extra mixer stage for band 1. Its probably the tube V103, but could
be the crystal or a band switch  contact. The band 1 mixer gets 8 MHz from a 
4 MHz crystal in the crystal oscillator that also drives the first mixer with 
12 MHz. That 4 MHz crystal is only used on band 1. Its Y110.

The holder won't be right but most distributors like Mouser and Digi-Key carry 
4 MHz crystals with wire leads for less than a buck. Such as Mouser 
695-HC49US-4-U or 520-HCA400-20X for 20 pf circuit or 520-HCA400-SX for 
series. And several others.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer