Re: [amsat-bb] Question about 13 cm. converter

["John P. Toscano" <tosca005@xxxxxxxxxx>]

Bill Richarz (N4DH) wrote:
 
> QUESTION:  I have a Hamtronics 2 to ten meter converter.
> Could I feed the 13 cm converter into the 2 meter converter
> and tune the 2.4 gHz band?

If you mean, 2400 converter -> 2-to-10 transverter -> HF radio,
then yes, it should work.  One potential limitation is that a
2M IF radio (in this country, at least) can tune over a 4 MHz
range, giving you 2400-2404 MHz, while a 10M radio may have a
substantially narrower tuning range.  Of course, this is a
receive-only application, so if your HF radio can RECEIVE
outside the ham bands, it may not even be a limitation.
Besides, the P3D/AO-40 band plan shows that you only need to
tune 2400.200 to 2401.950 to hear everything on S band that
the bird can generate, and the highest frequencies (which
might go above a 10M IF radio's tuning range) are the S2
digital downlink passband.

Specifically, AO-40's S-band transmission frequencies are:

 Frequency Range     Purpose        2M IF           10M IF
-----------------  ----------  ---------------  -------------
2400.200           S1 GB       144.200          28.299
2400.225-2400.475  S1 Analog   144.225-144.475  28.225-28.475
2400.350           S1 MB       144.350          28.350
2400.600           S1 EB       144.600          28.600
2400.650-2400.950  S1 Digital  144.650-144.950  28.650-28.950
2401.200           S2 GB       145.200          28.299
2401.225-2401.475  S2 Analog   145.225-145.475  29.225-29.475
2401.350           S2 MB       145.350          29.350
2401.600           S2 EB       145.600          29.600
2401.650-2401.950  S2 Digital  145.650-145.950  29.650-29.950

GB = general beacon, MB = middle beacon, EB = engineering beacon,
and S1 vs. S2 refers to the two different S-band transmitters, for
the benefit of a few lurkers who might not know that already.

So with the setup you propose, if your HF radio stops receiving
at 29.7 MHz, you would still be able to tune in the vast majority
of the S-band signals generated by AO-40.

John (KB0ZEV)
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