[Heathkit] HR-1680 Dead Band

[Rodger Singley]

I agree with Bob that you should start by checking the adjustment of the hetrodyne oscillator coil for that crystal.  Proper adjustment for reliable crystal operation is to set it just a little bit away from peak output on the side where output drops slowly.  If you can't get it to work make sure that the coil leads are intact.  Sometimes the core sticks and the leads get broken when the core is forced and the entire form rotates.  Often these breaks can be repaired.

If the crystal is bad the HR-1680 uses the same conversion scheme and HFO frequencies as the common 5 band HW and SB series rigs (i.e. SB-3XX, SB-4XX (if optional crystal pack was included), SB-1XX, HW-1XX) but NOT the HW monobanders.  It is much easier to find parts for these than the less popular HR-1680.

Rodger WQ9E

-------- Original Message --------
> From: "K5MYJ" <macklinbob at gmail.com>
> Sent: Wednesday, April 13, 2016 10:57 PM
> To: ka4inm at gmail.com>, "H" <heathkit at mailman.qth.net>, "Bwana Bob" <wb2vuf at verizon.net
> Subject: Re: [Heathkit] HR-1680 Dead Band
> 
> There is a coil for each crystal in the HR-1680.
> 
> The first step would be to try the adjustment instructions in the manual.
> 
> Bob Macklin
> K5MYJ
> Seattle, Wa.
> "Real Radios Glow In The Dark"
>