[Heath] SB-303 oscillator (BFO) question

[Kenneth G. Gordon]

On 6 Sep 2015 at 15:33, Robert Myers wrote:

> Another quick SB-303 oscillator based question:
> 
> When switching between USB and LSB modes on the SB-303 what are the two
> frequency values that the BFO should switch between (again, for the moment
> assuming the BFO is oscillating exactly on its spec´d frequency).

You should keep in mind that by this late date, ALL the crystals have drifted, 
and hardly any are on their original frequencies.

The heterodyne oscillator crystals are often a big problem now.

BFO crystals can drift so far that they are outside the passband of the filter, 
and the filter crystals can also have drifted.

SOME crystals can be "tweaked" back onto frequency by various methods, 
but some have to be simply replaced.

You may find this PDF of interest too:

http://www.w7ekb.com/glowbugs/ModsEtc/Heathkit%20SB_HW%20Filters.p
df

Ken W7EKB