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Hello Alan,

Wednesday, December 9, 2020

It's tweaked, but I'll have another go, thanks Alan.


Best regards,
Chris 2E0ILY mailto:chris@...


AG> But you can make out biits of images from the signals received on top
AG> band 1.933 MHz.

AG> Chris,

AG> This looks a if you need to tweak HDSDR's image adjustment.

AG> 73 Alan G4ZFQ


AG>

Hello Alan,

Wednesday, December 9, 2020

Could the issue be power supply overload if they share the same supply? I would have thought TX'ng into a dummy load on a short coax would be unlikely to get into the USB cable? Just an idea.


Best regards,
Chris 2E0ILY mailto:chris@...

Sounds like RF getting into the USB cable. Try one of those shielded
cables with ferrite chokes built in at both ends.

AG> Yes, there is nothing in the Softrock that is likely to do that.
AG> USB drop-out seems to confirm.

AG> 73 Alan G4ZFQ


AG>

Hello Nick,

Wednesday, December 9, 2020

Reducing output to the sound card didn't work, but adding a temporary adjustable attenuator seems to have worked. The issue is mainly on my big horizontal loop which probably is overloading the Softrock. I'll experiment over the next week then add something permanent if the buffer is unity gain. Thanks a lot everyone.


Best regards,
Chris 2E0ILY mailto:chris@...


N> Chris

N> There's not much wrong with the 'small signal' image rejection settings
N> for the softrock. As Alan says a tweak in HDSDR will improve it.

N> If you are seeing other spurii when receiving big signals you might be
N> overloading the the sound card, the softrock, or perhaps even the PAT.

N> The PAT 'manual' says

N> "The buffer has two active stages – a JFET source follower to present a
N> high impedance to the IF filter, and therefore minimise any loading on
N> the main signal path of the radio. This is followed by a BJT as an
N> emitter follower to provide impedance transformation for a following
N> filter stage. There are two passive stages following this – a 50R low
N> pass filter to limit the passage of signals above the IF, and a
N> resistive attenuator to allow the overall gain of the board to be
N> matched to the input requirements of the SDR."

N> Therefore one might expect the voltage gain of the PAT into a 50 Ohm
N> load to be somewhat less than 1. I do not know why Table 2 quotes the
gain as slightly >> 1 - perhaps termination or measurement errors?

N> The PAT 'manual' also says

N> "Similarly, there is the capability to place an output attenuator on the
N> PAT PCB, although in most cases it will not be needed – the value of the
N> attenuator may vary depending on the SDR to be used. It is preferable
N> that this attenuator, too, is provided off board, since it avoids
N> opening up the rig if the SDR is changed."

N> Yours could be one of the cases where an attenuator is needed - just
N> enough to stop the softrock or soundcard overloading on big signals.

N> Where exactly are you tapping off the IF signal from the TS590? If it's
N> before the AGC loop you need to take care to get the level right.

N> Can you put a 'scope on the tap point using a Hi-Z 10:1 probe to measure
N> what level you are getting in practice with big signals?

N> I would put a signal generator on the TS590 antenna input via a
N> calibrated step attenuator, and then make some 'scope measurements right
N> up to the sound card input so you can optimise the dynamic range of the
N> whole system.

N> NB: make sure the TS590 cannot accidentally go onto transmit and destroy
N> the step attenuator!

N> HTH.

N> Nick

N> On 08/12/2020 23:39, Chris Wilson wrote:

Hello again

Tuesday, December 8, 2020

Here you can see the data mode image and the 1920 kHz image shifted when I moved the slider, still not a great example, really big signals have glaringly obvious images.

Thanks.

Best regards,
Chris 2E0ILY mailto:chris@...

CW> Hello Alan and Nick,

CW> Tuesday, December 8, 2020

CW> I didn't see many very strong signals so this example is rather
CW> a weak image, it's definitely not seeing just one audio channel,
CW> it is only apparent with very strong signals. But you can make out
CW> biits of images from the signals received on top band 1.933 MHz.

CW> Please see

CW> Thanks.

CW> Not sure if the pre built buffer amp has gain or not, I'd have to
CW> pull it out of the TS-590 and examine it, thanks for the link.

CW> Best regards,
CW> Chris 2E0ILY mailto:chris@...

N>> On 08/12/2020 14:52, Chris Wilson wrote:

08 December 2020

I am using my Ensemble HF RX as a second receiver / panadapter for my TS-590. My buffer amp died and I bought a new one, I THINK it may have been mis-sold as not a unity gain one, but with gain as this effect wasn't noticed before. I now see two images equi spaced from the center when very strong antenna signals are present. Short of changing the buffer amp is there any trick to stopping this please? I haven't opened the 590 to check my fears yet, not sure there's even a schematic for the hupRF buffer I bought available... Thanks

N>> Chris,

N>> can you post a screenshot?

N>> Also see...

N>>

N>> Nick

N>

Sounds like RF getting into the USB cable.? Try one of those shielded cables with ferrite chokes built in at both ends.

Yes, there is nothing in the Softrock that is likely to do that.
USB drop-out seems to confirm.

73 Alan G4ZFQ

On 09/12/2020 16:05, Robert George wrote:

the RXTX shuts off the RF output and the USB connection to the computer laptop drops

Sounds like RF getting into the USB cable. Try one of those shielded cables with ferrite chokes built in at both ends.

HTH

Nick

I have a question about using the Softrock Ensemble RXTX with one of those cheap far east linear amp kits. I believe the amp is working correctly and I have set the bias voltage adjustment on the gates of the power MOSFETs (~1.0 vdc) and activated PTT (ground), I now adjust the output of the RXTX using a 2000 Hz test audio to the Line-In usine M0KGK IQ Test and use CFGSR to control PTT on the RXTX.

When adjusting the amplitude of the test IQ 2000 Hz signal to ~ -10dB with PTT active on the RXTX the power amp kicks in (output at the dummy load) and then, less then one second, the RXTX shuts off the RF output and the USB connection to the computer laptop drops.

What is the most likely cause of the RXTX RF shut off? Is it DC ground loop, RF back feeding the Softrock or sloppy connections between components? I would appreciate any input form any of you who have successfully used the RXTX with a RF power amplifier, especially the cheap kits form E-Bay and Alliexpress.

Chris

There's not much wrong with the 'small signal' image rejection settings for the softrock. As Alan says a tweak in HDSDR will improve it.

If you are seeing other spurii when receiving big signals you might be overloading the the sound card, the softrock, or perhaps even the PAT.

The PAT 'manual' says

"The buffer has two active stages – a JFET source follower to present a high impedance to the IF filter, and therefore minimise any loading on the main signal path of the radio. This is followed by a BJT as an emitter follower to provide impedance transformation for a following filter stage. There are two passive stages following this – a 50R low pass filter to limit the passage of signals above the IF, and a resistive attenuator to allow the overall gain of the board to be matched to the input requirements of the SDR."

Therefore one might expect the voltage gain of the PAT into a 50 Ohm load to be somewhat less than 1. I do not know why Table 2 quotes the gain as slightly > 1 - perhaps termination or measurement errors?

The PAT 'manual' also says

"Similarly, there is the capability to place an output attenuator on the PAT PCB, although in most cases it will not be needed – the value of the attenuator may vary depending on the SDR to be used. It is preferable that this attenuator, too, is provided off board, since it avoids opening up the rig if the SDR is changed."

Yours could be one of the cases where an attenuator is needed - just enough to stop the softrock or soundcard overloading on big signals.

Where exactly are you tapping off the IF signal from the TS590? If it's before the AGC loop you need to take care to get the level right.

Can you put a 'scope on the tap point using a Hi-Z 10:1 probe to measure what level you are getting in practice with big signals?

I would put a signal generator on the TS590 antenna input via a calibrated step attenuator, and then make some 'scope measurements right up to the sound card input so you can optimise the dynamic range of the whole system.

NB: make sure the TS590 cannot accidentally go onto transmit and destroy the step attenuator!

HTH.

Nick

But you can make out biits of images from the signals received on top band 1.933 MHz.

Chris,

This looks a if you need to tweak HDSDR's image adjustment.

73 Alan G4ZFQ

Hello again

Tuesday, December 8, 2020

Here you can see the data mode image and the 1920 kHz image shifted when I moved the slider, still not a great example, really big signals have glaringly obvious images.



Thanks.


Best regards,
Chris 2E0ILY mailto:chris@...


CW> Hello Alan and Nick,

CW> Tuesday, December 8, 2020

CW> I didn't see many very strong signals so this example is rather
CW> a weak image, it's definitely not seeing just one audio channel,
CW> it is only apparent with very strong signals. But you can make out
CW> biits of images from the signals received on top band 1.933 MHz.

CW> Please see

CW> Thanks.

CW> Not sure if the pre built buffer amp has gain or not, I'd have to
CW> pull it out of the TS-590 and examine it, thanks for the link.


CW> Best regards,
CW> Chris 2E0ILY mailto:chris@...


N>> On 08/12/2020 14:52, Chris Wilson wrote:

08 December 2020

I am using my Ensemble HF RX as a second receiver / panadapter for my TS-590. My buffer amp died and I bought a new one, I THINK it may have been mis-sold as not a unity gain one, but with gain as this effect wasn't noticed before. I now see two images equi spaced from the center when very strong antenna signals are present. Short of changing the buffer amp is there any trick to stopping this please? I haven't opened the 590 to check my fears yet, not sure there's even a schematic for the hupRF buffer I bought available... Thanks

N>> Chris,

N>> can you post a screenshot?

N>> Also see...

N>>

N>> Nick







CW>

Hello Alan and Nick,

Tuesday, December 8, 2020

I didn't see many very strong signals so this example is rather a weak image, it's definitely not seeing just one audio channel, it is only apparent with very strong signals. But you can make out biits of images from the signals received on top band 1.933 MHz.

Please see

Thanks.

Not sure if the pre built buffer amp has gain or not, I'd have to pull it out of the TS-590 and examine it, thanks for the link.


Best regards,
Chris 2E0ILY mailto:chris@...


N> On 08/12/2020 14:52, Chris Wilson wrote:

08 December 2020

I am using my Ensemble HF RX as a second receiver / panadapter for my TS-590. My buffer amp died and I bought a new one, I THINK it may have been mis-sold as not a unity gain one, but with gain as this effect wasn't noticed before. I now see two images equi spaced from the center when very strong antenna signals are present. Short of changing the buffer amp is there any trick to stopping this please? I haven't opened the 590 to check my fears yet, not sure there's even a schematic for the hupRF buffer I bought available... Thanks

N> Chris,

N> can you post a screenshot?

N> Also see...

N>

N> Nick


N>

On 08/12/2020 14:52, Chris Wilson wrote:

08 December 2020
I am using my Ensemble HF RX as a second receiver / panadapter for my TS-590. My buffer amp died and I bought a new one, I THINK it may have been mis-sold as not a unity gain one, but with gain as this effect wasn't noticed before. I now see two images equi spaced from the center when very strong antenna signals are present. Short of changing the buffer amp is there any trick to stopping this please? I haven't opened the 590 to check my fears yet, not sure there's even a schematic for the hupRF buffer I bought available... Thanks

Chris,

can you post a screenshot?

Also see...



Nick

Chris

see two images equi spaced from the center

Two images?
What do you mean?
The true signal+ image or something else?
If it is the first are they identical? Then suspect a missing audio channel.
If not then you could use an attenuator.

73 Alan G4ZFQ

08 December 2020


I am using my Ensemble HF RX as a second receiver / panadapter for my TS-590. My buffer amp died and I bought a new one, I THINK it may have been mis-sold as not a unity gain one, but with gain as this effect wasn't noticed before. I now see two images equi spaced from the center when very strong antenna signals are present. Short of changing the buffer amp is there any trick to stopping this please? I haven't opened the 590 to check my fears yet, not sure there's even a schematic for the hupRF buffer I bought available... Thanks



--


Best regards,
Chris mailto:chris@...

Found! Thank you Jon!

Curt

GE All:

I am looking for links to the documentation package for the 6m/4m/2m RX Ensemble 1 kit . Board is 2011 purchased kit in 2012.

THis is NOT the converter board version.

Thanks,

Curt.

Great to hear that the Softrock works very well in digital modes and you got lots of awards. In fact these little things are very flexible and offer to the users the advantage to understand and get most out of the product. The fact it works well with digital modes corroborate my? it understanding it as a good dynamic range. In the CW contest I could see low signals near to the strongest ones.

By the way in the message above I made a typo: I wrote "I ended up with 550 QSOs. There were a few dupes and excluding mistakes I believe the valid QSOs should be above 200". It should be read "I ended up with 550 QSOs. There were a few dupes and excluding mistakes I believe the valid QSOs should be above 500." The fact is that I had never made 350 QSOs in just one day before (in contest teams, I admit, I am the black sheep, because of my low rate), given my antenna set-up and the rather modest power (between 20 and 50w), searching and pouncing.

Merry Softrock!

Franco iz2oos

I haven't done any contests, but have been using a Softrock RX/TX for the last 3 years for digital modes, did DXCC, WAS, and many other awards with it. I had to build a little QRP amp with alot of gain (my own Homebrew, single MRF455 transistor) to go behind it, and that in turn drives my AL-811H when I need it. Have thoroughly enjoyed my Softrock products, have been a customer since about 2013. I used 5 of the Softrock RX Lite kits to run my own WebSDR server for many years before going to dongles/upconverters.

I am rather impressed how nice operating the Softrock Ensemble RXTX during the CQ WWDXCW contest had been. I ended up with 550 QSOs. There were a few dupes and excluding mistakes I believe the valid QSOs should be above 200. On Sunday I did 350 QSOs, all searching and pouncing. It was paired with a small PA (50w on 40m decreasing to 20w on 10m) and an old poor and oxidized T2FD antenna. Of course I used the latest Quisk version available (better image rejection). Absolutely fantastic, no issue at all with narrow dynamic range. Thousands of clean signals popping up out of the screen.

I have one of these, it is great.

Garry,
You're not the only one who replied to me with that same PCB holder. I like it. I do see however a place for both in the shop. I have both in my cart and will save them so when I get my SS Disability meager Pittance, I can get them.

Thanks for the response.

--
73/72 . .
Bob de k2ki
k2ki@...
k2ki.bb@... (Goes to my cell)
NEQRP #911
4SQRP #2292
FP #4214
SKCC #12195
NAQCC #2337

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