[Heathkit] SB-620/HO-13

[Robert & Linda McGraw (K4TAX)]

Yes, original coils and caps are nice to have.  I've never bought a SB-620 
that had the extras supplied with the kit.  I guess most get tossed after 
the unit is assembled for the current user's IF.   At the same time, Surplus 
Sales of Nebraska and Mouser sells adequate materials to put them on any IF 
freq you may desire.

Basically the SB-620 is a receiver with a 350 KHz IF frequency.  One will 
need a suitable variable inductor for the input, that's L1, based on your 
needed IF frequency. A second inductor for the mixer which is 350 KHz plus 
your IF frequency, that's L2 and a tapped inductor for the local oscillator. 
That's L3.

The R's and C's are in the manual and are shown on the schematics for the IF 
frequencies you'll need.  You'll need to figure the required L values. 
There's LC calculators on the internet that do this quite nicely.

73
Bob, K4TAX


----- Original Message ----- 
From: "Rick Brashear" <rickbras at airmail.net>
To: <Heathkit at mailman.qth.net>
Sent: Thursday, March 01, 2007 9:58 AM
Subject: [Heathkit] SB-620/HO-13


> Since I inquired about the SB-620 I have learned a lot thanks to the 
> knowledge of this list.  Never having owned or even touched one of these 
> monitors I was unaware of how the different IF frequencies were 
> determined.  Now I know it is necessary to have the accompanying coils and 
> capacitors which shipped with the original unit.  So, here is my request 
> for those items.  If anyone happens to have spare coils/capacitors for 
> this purpose I would sure like to discuss buying them.
> Thanks,
> Rick/K5IZ
>
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