HDSDR & Tx questions

General discussion and support for the Peaberry SDR V2.

HDSDR & Tx questions

Postby pilotcfii » Mon Mar 09, 2015 1:59 pm

I have had several JT65 QSO's using the PB and have received good signal reports (@ 200mW indicated output) but of course I am not yet satisfied that the signal is clean enough. When I run through the Tx alignment as shown on page 25 of the assembly instructions, I can't the the adjustment making any difference in the signal. During a QSO though I see several signals adjacent to my main signal on my monitoring receiver. The monitoring receiver is a Yaesu FT-950 that is disconnected from an antenna but is connected to the same Alpha-Delta antenna switch the PB is connected to. That leads me to believe I have some cleanup work to to. Any help here would be appreciated.

Second problem is with HDSDR. When I first start up the PB/HDSDR/HRD/WSJTX chain, I find it's necessary to stop at the HDSDR point and exercise the Tx button. If I don't I will later have problems the Tx from HRD. First there will be a 1 or 2 second delay in Tx start and then at the end of the Tx period, Tx may not stop. In order to stop Tx, sometimes clicking the HDSDR Tx button will work but usually I need to just power off the PB, and then restart all the software. HDSDR is set to use the HRD (DDE) button.
73
Dan Malcolm
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Re: HDSDR & Tx questions

Postby AE9RB » Tue Mar 10, 2015 4:24 pm

Half-power and the inability to null the TX image means one of the two I/Q signals of the transmitter is not connected or both channels are shorted together. Either way you are looking for soldering errors.

However, you said Peaberry CW puts out 2W. That is definitely not half-power. So maybe you have a software problem.

Not sure why HRD has trouble keying HDSDR. I don't use HRD. This also smells like software.
73 David AE9RB
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Re: HDSDR & Tx questions

Postby pilotcfii » Tue Mar 10, 2015 8:58 pm

AE9RB wrote:Half-power and the inability to null the TX image means one of the two I/Q signals of the transmitter is not connected or both channels are shorted together. Either way you are looking for soldering errors.

Is there an easy way to test for this short of an O'scope? I am limited to a DMM.

AE9RB wrote:However, you said Peaberry CW puts out 2W. That is definitely not half-power. So maybe you have a software problem.

Entirely possible. I will keep playing with levels. I am using a monitoring receiver, and trying to be judicious with audio levels as excess audio level has proven to cause overdrive problems in other rigs that have ALC.

AE9RB wrote:Not sure why HRD has trouble keying HDSDR. I don't use HRD. This also smells like software.

I don't disagree but once I can reliably key/unkey Tx in HDSDR, HRD will also key reliably. This is usually solved by exercising Tx in HDSDR, before allowing HRD to connect. I think this one is an HDSDR setup problem, so I will attack this first.
73
Dan Malcolm
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Re: HDSDR & Tx questions

Postby pilotcfii » Thu Mar 12, 2015 2:59 pm

AE9RB wrote:Half-power and the inability to null the TX image means one of the two I/Q signals of the transmitter is not connected or both channels are shorted together. Either way you are looking for soldering errors.


The term "both channels" sounds like the I/Q signal should be transported via stereo connections. If true I may have a hint at my problem. WSJT-X is set for Mono for the sound card. It has selections for LEFT and RIGHT that I can use, but the selection for BOTH is greyed out. It may be that's because the virtual audio cables are not set up correctly. I have looked but have not been able to define the vac's as either stereo or mono.
73
Dan Malcolm
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