[Heathkit] SB-620 info

[manualman@juno.com]

What frequency is it setup for now? Per the manual, changing to a
different IF requires changing some parts. Or, if you know the IF the
SB-620 is setup on, a simple outboard mixer to take the receiver signal
and either up-convert or down-convert to the IF setup in the SB-620. I
remember CQ magazine had an article on doing this with the HO-13.
Pete

On Thu, 12 Jun 2003 07:51:52 -0400 Jim Brannigan <jbrannig@optonline.net>
writes:
> I am taking another run at converting the SB-620 "Scanalyzer" to a 
> 455kc. IF
> 
> Does anyone know the mixer oscillator injection frequency for a 
> 455kc
> conversion?  It is not
> stipulated in the manual or on-line sources.
> 
> Here is my guess:
> The IF of the Heath "Scanalyzer" is 350kc.
> To convert 455kc., the oscillator may be either 805 or 105kc.
> The "high" injection of 805kc produces first order products of 350 
> and
> 1260kc.
> "low injection of 105kc produces 350 and 560kc.
> 
> The "High" injection products are further apart and it would be 
> easier to
> filter the unwanted sum frequency.
> So my "guess" is 805kc.
> I know the value of the parallel capacitance.  If the oscillator 
> frequency
> is known, I can calculate the coil inductance.
> 
> Any help or ideas greatly appreciated.
> 
> Jim> _______________________________________________

________________________________________________________________
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!