Duplex hat to work as simplex

[IZ4FXT]

Hi all,
Just for doing some rx comparation, I would like to put my duplex hat in simplex mode.
I read something about that some time ago, but i can't find it anymore.
There was written in that case only one of the adf7021 (tx OR rx of the duplex) remain in work both for rx and tx, the other one off.
The question is:witch one of the two remain active in both ways? The original rx OR the original tx side?
And BTW : it is sufficient to put duplex off in pistar and put same fq for tx and rx, or i have to take a look anywhere ( Config.h and so on)?
Thank you

[W8DEX]

Hi I have a duplex too. I don't remember which one stays on or off, but it should easy enough to test with a dummy load and an antenna.
I had it working simplex once, but I have switched back to duplex.

What are you trying to do?

By the way, I have found it very hard to get any answers out of this forum.
I also think your question should be directed to some mmdvm group instead as pi-star is mainly a front-end.

Good luck.
Cheers

[IZ4FXT]

Hi w8dex,
Thank you for Your answer, i'm suffering bad rx in duplex, very short range of about 50m with 6cell duplexer and external ant also with high gain setting , but simplex dvmega hat and openspot with right setting , are much better about 1km,same rf chip.
So, now i want to try my duplex hat in half duplex, just to know if the range remain the same without any kind of separation problem.
73&51 IZ4FXT

[AF6VN]

Hi w8dex,
Thank you for Your answer, i'm suffering bad rx in duplex, very short range of about 50m with 6cell duplexer and external ant also with high gain setting , but simplex dvmega hat and openspot with right setting , are much better about 1km,same rf chip.
So, now i want to try my duplex hat in half duplex, just to know if the range remain the same without any kind of separation problem.
73&51 IZ4FXT

Are you testing the DVMega/OpenSpot with them feeding through the duplexer also? (Granted, you'll only be able to test in one direction at a time due to cable connections). If the signal path is not identical (antenna, duplexer/circulator, cables -- everything except the "hat") it is an unfair comparison.

[W8DEX]

I have replaced the original antennas with 2 Nagoya NA-771 and the hotspot is indoor.
I get about 1/4 mi in range in a hilly area.

I have never tried with an external antenna.

Sounds like you might have some other setup issues.
I did not have to change anything but the antennas.

WIN_jumbospot_771.jpg (167.79 KiB) Viewed 5009 times

Cheers

[IZ4FXT]

@AF6VN for dvmega and openspot obviously tried without duplexer, but tried the duplex without the duplexer and with same antenna in rx plus another some meters away in tx, but nothing different... Same poor rx

@W8DEX very interesting your experience. Also because of the two antennas are so near each other, and despite of that good result! A dream for me My results are worst, so, or i have an hardware problem (bi7jta 1.0.1 board) or as You said it's a configuration matter, but with pistar was straightforward, also offsets are setted for low ber. Have You any suggestion to me to try?

Thank You both!!!

[W8DEX]

The tx/rx frequencies are spaced 5mhz on the UHF band so they should be far apart enough not to create any reciprocal interference.
In fact, I have been monitoring activity with a separate radio and there is no interference that affects the hotspot or the radio.

Do you have the same type of duplex jumbospot?
Did you check that the sma connector is properly soldered? sometime a bad soldering job can affect performance.
Might just be a bad hotspot one too.

What kind of radio are you using? HT, mobile? and what power do you use to transmit?

I use 1w in the house cause that is the lowest the radio can go, but I can bump it up to 2w or 10w when I leave the house and walk the neighborhood up to 1/4mi. But I have indoor antennas and a hilly location so I get a lot of attenuation when I walk away from the house.

Cheers