VHF downconverter recommendations?
I had an email from someone asking for a recommendation of a VHF downconverter for the Kiwi. One that covered more than just the 2m band. Can anyone suggest something?
I did review these threads, but I was looking for a simpler (e.g. one board) solution.
http://forum.kiwisdr.com/index.php?p=/discussion/1836/my-airband
http://forum.kiwisdr.com/index.php?p=/discussion/1517/diy-downconverter
Thanks in advance.
Comments
Hi John,
Mine only covers 1 band but the transverter board used also has a 70cm version.
http://forum.kiwisdr.com/index.php?p=/discussion/2171/kiwi-with-2m-converter-switch-added#latest
To answer my own question: This guy in Ukraine sells very reasonably priced transverter boards/boxes for individual ham bands to the top end of HF. Note there are several different models per band that use different oscillator frequencies (e.g. 144:148 => 28:32, 144:148 => 26:30, 146:150 => 26:30) and also models that have a more expensive TCXO rather than a crystal.
https://www.ebay.com/sch/m.html?_dmd=2&_ssn=transverters-store&_osacat=0&_armrs=1&_sop=15&_odkw=&_from=R40&_trksid=p2046732.m570.l1313&_nkw=transverter&_sacat=0
I've not examined recent products from the Ukraine but I can not recommend the earlier transverters. Perhaps the receive converters are different/better.
How much interest would there be in the creation of a fast-switching block down-converter for the Kiwi? This would be something with a high side, say 3 GHz IF preceded by a [20 MHz] stepping LO that went from, 3-6 GHz, mixer and LPF?
The result would be an "all band" down-converter one [20 MHz] swath at a time such that the Kiwi could use any of it's capabilities over 0-3 GHz? NF and IMD could be good and no additional filtering would be necessary as long as out-of-band signals were kept tolerably low compared to a mixer's spec. +20 dBm TOI should be fairly easy. Of course, filtering could be added at the input, as for a band-limited converter of the type most often used.
It would seem to me that a Kiwi extension to use I2C to control the LO/receive_frequency should not be difficult. The goal would be fast switching so that multiple 20MHz chunks might be stitched together to create a wider spectrogram.
Glenn n6gn