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Low power readings on an Ensemble RXTX,could it be a PTT problem?

jstockma@yahoo.com
 

I have almost completed an Ensemble RXTX., All the voltage tests in the WB5RVZ documentation have checked out out until I tested the power output at the BNC jack. I am only getting ?voltages using an RF probe ?in ?136mV range.With Rocky in Transmit/Tone mode. ?I put a USB scope to the driver transistor case and only saw a very low voltage clean sine wave. This would appear to indicate a bad driver stage. ?thinking that I had damaged the leads on the driver transistor I replaced it with no change in the ?readings. I have rechecked the orientation of the driver transistor and I am pretty sure that the EBC orientation is ok.

I am beginning to think that radio is working ?properly but that it is an ?issue with PTT USB connection with my PC. I am using an ACER netbook running XP ?with Rocky installed and a Soundblaster external sound card. At ?the risk of embarasing myself I need feedback on whether I have everything hooked up properly. ?As it is, I have the line in connected to the line in on the external soundcard and the line out connected to the phones jack ?on that ?soundcard. I have the USB cable connected from the USB port on the RXTX to one of the USB ports on the ?ACER and the USB cable from the external soundcard connected to another USB port on the ACER. I do not have any mike or speakers connected to the mike and headphone jacks on the PC. I have configured Rocky's settings to run the I/Q to the external soundcard and to run the audio and mike to the Acer's internal soundcard. Could it be that the USB from the RXTX is not gettting any PTT signal from the USB connected to the ACER? I am very new to SDR and I am thinking that it is a PTT issue. Everything checked out up to the power output testing.
jstockma@yahoo.com
 

John Stockman,KC2THY authored the starting message in this thread.
 

Stereo card?


On Tuesday, April 8, 2014, <jstockma@...> wrote:
?

I have almost completed an Ensemble RXTX., All the voltage tests in the WB5RVZ documentation have checked out out until I tested the power output at the BNC jack. I am only getting ?voltages using an RF probe ?in ?136mV range.With Rocky in Transmit/Tone mode. ?I put a USB scope to the driver transistor case and only saw a very low voltage clean sine wave. This would appear to indicate a bad driver stage. ?thinking that I had damaged the leads on the driver transistor I replaced it with no change in the ?readings. I have rechecked the orientation of the driver transistor and I am pretty sure that the EBC orientation is ok.


I am beginning to think that radio is working ?properly but that it is an ?issue with PTT USB connection with my PC. I am using an ACER netbook running XP ?with Rocky installed and a Soundblaster external sound card. At ?the risk of embarasing myself I need feedback on whether I have everything hooked up properly. ?As it is, I have the line in connected to the line in on the external soundcard and the line out connected to the phones jack ?on that ?soundcard. I have the USB cable connected from the USB port on the RXTX to one of the USB ports on the ?ACER and the USB cable from the external soundcard connected to another USB port on the ACER. I do not have any mike or speakers connected to the mike and headphone jacks on the PC. I have configured Rocky's settings to run the I/Q to the external soundcard and to run the audio and mike to the Acer's internal soundcard. Could it be that the USB from the RXTX is not gettting any PTT signal from the USB connected to the ACER? I am very new to SDR and I am thinking that it is a PTT issue. Everything checked out up to the power output testing.
 

Your setup sounds like it is connected in a way that should work. But I am not clear if you have setup Rocky correctly.

On the Settings/Audio screen I/Q Input Device should be set to the Line In of your external USB Card. Audio Output Device should be set to your internal laptop sound device. This will allow you to hear the received signals on your laptop speakers.

On Settings/Transmit you should set I/Q Output Device to the the device that corresponds to the Phones setting of your external USB card.

In other words, for the way you are connected, I/Q in and out should be from your external card and Audio Output should go to the laptop internal card.

Hope that helps

Warren Allgyer
W8TOD (this week only)


---In softrock40@..., <jstockma@...> wrote :

I have almost completed an Ensemble RXTX., All the voltage tests in the WB5RVZ documentation have checked out out until I tested the power output at the BNC jack. I am only getting ?voltages using an RF probe ?in ?136mV range.With Rocky in Transmit/Tone mode. ?I put a USB scope to the driver transistor case and only saw a very low voltage clean sine wave. This would appear to indicate a bad driver stage. ?thinking that I had damaged the leads on the driver transistor I replaced it with no change in the ?readings. I have rechecked the orientation of the driver transistor and I am pretty sure that the EBC orientation is ok.

I am beginning to think that radio is working ?properly but that it is an ?issue with PTT USB connection with my PC. I am using an ACER netbook running XP ?with Rocky installed and a Soundblaster external sound card. At ?the risk of embarasing myself I need feedback on whether I have everything hooked up properly. ?As it is, I have the line in connected to the line in on the external soundcard and the line out connected to the phones jack ?on that ?soundcard. I have the USB cable connected from the USB port on the RXTX to one of the USB ports on the ?ACER and the USB cable from the external soundcard connected to another USB port on the ACER. I do not have any mike or speakers connected to the mike and headphone jacks on the PC. I have configured Rocky's settings to run the I/Q to the external soundcard and to run the audio and mike to the Acer's internal soundcard. Could it be that the USB from the RXTX is not gettting any PTT signal from the USB connected to the ACER? I am very new to SDR and I am thinking that it is a PTT issue. Everything checked out up to the power output testing.
 

A quick way to know if the RXTX is being keyed by the PTT signal is to measure the voltage on the hairpin of R35. The is the "S12" signal and it will be 0 volts in receive mode and 12V in transmit.

Another quick check if your 12 supply has a current meter is you will see the current draw increase go up dramatically when you switch to transmit.

But make sure you set up Rocky correctly first!

Warren Allgyer
W8TOD
jcs1@msn.com
 

Made sure that Rocky's audio and I/Q were configured correctly and measured transmit and receive voltages on the hairpin of R34. Both were zero, so it looks like the transmit is not being keyed. Measured 12.8 V on R35 so its not my power supply. I set Rocky to transmit/tone mode which should result in a signal. It's back to the schematic for next steps and I will re-install the driver and Rocky again to make sure.I thank you and would welcome any further advice
?John Stockman, KC2THY
jcs1@msn.com
 

Correction, 0V on R35 and 12.8v on R34.
John Stockman, kc2thy
jcs1@msn.com
 

I reinstalled the USB driver, CFGSR, and Rocky. I get 0V on R35 with Rocky in transmit mode, but get 13V on R35 when I activate PTT from CFGSR, with Rocky off. Also get a much higher voltage on the BNC jack( .68V vs .163mV) It looks like a software problem. The USB is triggering PTT., ?Was not getting those reading before reinstalation..Will look at Rocky and how I have it set, may also try another SDR program.
jcs1@msn.com
 

Success, installed HDSDR and the ExtIO DLL, set it to transmit with DL6IAKs tone generator and got 8.46 V on the RF probe at the bnc jack.
John Stockman, KC2THY

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