SV9RYG did you pass in exams?
Thank's for your interest. Yes I passed and now I'll study Computer Science at University of Crete (my first choice).
Now I've been working in Heraklion and due to work the QO-100 project has been frozen, but I'll keep this thread updated for everything new.
Best 73 de SV9RYG
I will make so experimens with 1n4148 and BAT85 and I will choose then.
Actually I thought about pluto/lime etc full duplex sdr solutions but I want
a PC free solution . GPSDO will propably be the last part I will check because
of their high prices but I'm pretty sure I'll try something homebrew based on
LARS gpsdo controlled by an arduino. Though I have no idea yet about how I could
get the 25mhz ext. reference (via the GPSDO ofcource, but how?!), but I'll do my
research on it by the time everything else is tested!
I was thinking of HMC-213 frequency mixer! Any other suggestions for a mixer?
I think I will change RX to TX path with 1n4148 diode though, it seems much more
safe than realys, although I was thinking of something like this circuit .
Hello again and thanks for your answers!
Sorry for my late reply but I've got a lot of studying for my exams this June.
I checked all your replies and last night I designed this block diagram for a QO-100
up/down converter! I got some ideas from IU8CRI,SV1ELF,BG0AUB,SV9OFO and checked also a lot of
similar projects in this forum and on FB groups. I think it will work just fine even without an external
reference from the beginning, but with a modified PLL TCXO LNB. I ordered some componnents from ebay
and I'll start experimenting with this project and I will keep you updated for more infromation but mostly
with even more questions haha!
I would be glad to hear your comments and suggestions for this block diagram!
( I will build each part seperatly first RX and then TX and after I check that everything works fine
I will put them all together)
73 de SV9RYG
Hi,
Just for the history my first QO100 transmission was with a laptop controlling a ADF4351 at 2.4 GHz , two amplifiers producing 3W and a homebrew helix powered from two lead acid batteries !!!
So it actually can be done?
Due to my low budget and the downconveter using adf4351 and the fact that I have only HF/50/70 radio (IC-7300)
I hope that I can do it all in one box using the same adf4351 for RX/TX generating freq (controlled from arduino and possibly having
an external reference) and some relays changing the "RF paths".
Thank's for your quick replies.
Due to the fact that in the current block diagram i use adf4351 signal generator
I thought it would be cool to use it for mixing also the current TX IF with 2.4ghz and
transmitting that way! I had the idea from a facebook from someone who claims that
that's the way he transmits on 2.4ghz but he didn't reply to my message for further information.
I actually have not at all experience on microwaves haha that's why i posted this thread just to check
if this thought could actually work somehow!
Hello everyone!
I've seen some people using a downconverter similar to this downconverter (check block diagram)! I've designed
it considering IU8CRI and SV1ELF work .
I'm not expert at all so I don't know if what I'm thinking for a homebrew upconverter will work!
If I generate a 2.4ghz freq via an adf4351 signal generator and mix that freqeuncy with an IF from my IC-7300 (on 28/50 etc mhz), and add some amps and BPFs will it work for transmitting on QO 100 ?
Has anyone done something simillar? I don't even know if it can be done but I hope you will be able to give me some advices.
(also any suggestions for the downconverter's block diagram will be really helpfull)
73 DE SV9RYG
