On Tue, 10 Feb 2009 11:39:29 -0500, Michael Black wrote:

On Tue, 10 Feb 2009, Tim Wescott wrote:


If it's the latter -- well, the same place may have what you want, or
you may be out of luck (did the Heath rigs _have_ an AM selection?
Mine certainly didn't), or you may have to mix to some other frequency
(i.e. 455kHz), filter, and mix back. Note that my SB-201 didn't have
an AM detector, either, so it may be more than just a filter that you
need.

If they kept the same IF frequency, and I know the SB line did use
something in the 3MHz range, then there was at least one AM filter, for
the shortwave band version of the SB series receiver, the SB-313 or
something.

There was a Heathkit receiver/transmitter set for AM about the time of
their early SSB rigs, same sort of styling as the SSB rig of the time.
The era of the Indian names. I don't know whether those used a high IF
or used the traditional 455KHz, but if it was the former, they'd surely
use the same 3MHz range scheme as the SSB equpment.

Michael

I believe there was a regular brand rig (Kenwood?) of about that era that
also used the same mixing scheme, and had the same frequency fixed IF, if
not all the same matching impedances. I can't really recall, though,
other than I was thumbing through a replacement filter catalog and
noticed it because I had the SB-201.

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