[hpsdr] Possible 5 band VHF transverter?

[Andrew]

Hi Conrad,
Whilst it's a shame to throw away the fantastic phase noise performance of Hermes by using a PLL with internal VCO as they are so poor, its a good call for you as they are quite easy to work with and as you say, you don't actually need the performance of a crystal and the frequency agility is a bonus for a multi-band design. 

As a matter of interest, the SI-570 is somewhat superior and would give you phase noise performance at 10kHz offset of about -132dBc/Hz on 144MHz but you can't phase lock it to an external reference so probably a bit limited.
I too am looking at designing a transverter for Hermes as my main interest is VHF/UHF, I say main interest but actually Hermes has got me quite a bit interested in HF also these days!
I need it for more demanding applications like contests so will be going for a more traditional but up to date design using a crystal based oscillator and diode ring mixers.
I had an idea to combine the outputs of two transverters say for 144 and 70MHz with different IFs so that with the two or more receivers in Hermes I could monitor two bands at once!
Hope you project goes well.
73's,
Andrew
G4XZL
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