Posted on 01/05/2021 8:12:07 AM PST by tbw2
A while back we heard a suggestion that it may be possible to use the 5th harmonic on R820T2 RTL-SDRs to receive frequencies much higher than the normal 1.766 GHz limit. After mentioning this to to Hayati Augen he has recently managed to implement this driver hack, and now R820T2 based RTL-SDRs can tune all the way up to 6 GHz if Hayati's experimental driver branch is used.
Before everyone gets too excited, we need to temper expectations as sensitivity reduces the higher the frequency so an LNA may be required, imaging/aliasing is a major problem, and you will absolutely require a ~1.7 GHz high pass filter to be able to actually see any signals as otherwise the lower bands drown everything out. So when combined with the relatively small bandwidth of the RTL-SDR, the overall usefulness of this feature may be very limited, however it is great that this option at least now exists.
In order to actually receive anything, you will need to filter out all signals below about 1.7 GHz, otherwise they will alias on top of your desired frequency. We used the VHF-1760+ from Mini-Circuits. There are other options available as well, however this filter seems to work well as long as the signals below 1.7 GHz are not too strong.
(Excerpt) Read more at rtl-sdr.com ...
Are you someone a newbie to HAM hardware should consult with? If so I will have lots of questions for you about most cost efficient reliable solutions to doing secure packet and voice radio HF comms over short and long ranges (like a few hundred to 1500 miles). If SDR allows for the same hardware to do HF plus other bands, then I’ll absolutely take informed recommendations. My main budget goes to metals, like lead, copper, brass...so I am not looking for the limousine radio, just the utility vehicle equivalent. :)
I am not a ‘ham’ my self, but have been around it all my life.
I’m an electronics communications specialist and work in HF, VHF and microwave, up to 4kw..........................
Thanks, I appreciate the links you sent. I just need someone to guide me through building a shopping list so that I dont spend a lot of cash on the wrong stuff or have it not work together the way I envision it. I have been around this stuff but not kept up with all the converging tech that is available. I assume any modern set will be able to connect to a laptop and send packets, but I have never done it myself. Likewise I dont know how versatile in bands I can expect a transceiver can be given the advances in SDR.
We used to have a Ham Radio Ping List run by a Freeper Denver Ditdat, but checking his name seems he hasn’t posted since 2006.
Thank you.
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