[Heathkit] coils for SB610 and SB620

[Tom NØJMY - AAR7FV]

I've got it someplace.  I'll look for it.  I've purchased replacements 
for it that were made by ECG in years past.  They worked just fine.

73,
Tom

Jim Brannigan wrote:
> Further to the coil issue is the varactor diode.
> I've been reluctant to experiment with the coils for fear of blowing 
> the varactor diode.
> Does anyone know the part#, value, parameters, etc. for this part?
>
> Jim
>
>
>> Okay.  For Mike and anybody else interested: I've done a little more 
>> research and have come up with further info regarding the difference 
>> between the coils in a SB-620 vs. those in a HO-13.  The "dummy" 
>> terminal on the SB-620's coil *is* used as a solder tie-point, though 
>> it is *not* connected to the coil itself.  The resistors which make 
>> up the voltage-divider for the sweep-width switch are attached to it, 
>> as is the lead to the switch itself.   The HO-13 coils (40-588 or 
>> -589) do not have this "dummy" terminal, but are electrically 
>> identical to the 40-775 or -776, respectively, in the SB-620.  I 
>> *assume* they could be used to replace these coils - you would just 
>> have to provide an isolated terminal somewhere nearby as a substitute 
>> for the "dummy".  And it seems logical that these coils from a SB-620 
>> would be a drop-in replacement for the corresponding ones in a HO-13.
>>
>> Of course, this is all based on the shaky premise that you can find 
>> any of these coils in the first place.
>>
>> Oddly enough, my manual lists terminal lug #2 as the "dummy", but the 
>> engineering blueprints list it as terminal #4.  Oh, well.
>>
>> FWIW, the coils for the HO-13 are 40-588 (455-1681 kHz.) and 40-589 
>> (2075-3395 kHz.)..  The coils for the SB-620 are 40 -774 (not sure 
>> what i.f. range, apparently replaced by the -808? or was it the 
>> -807?), -775 (455-1000 kHz), -776 (3000-3395 kHz.), -807 (5200-6000 
>> kHz.), and -808 (1600-2445 kHz.).
>>
>> 73,
>> Tom
>
>