softrock40@groups.io

SDR Isolation from Xmitter (or Transciever )

All;
Sorry for crossposting this.. but I thought it may be of interest here
I asked this question on the SDRPLAY users group.
------------------------
Hi all;
I have an RSPlayduo.  I am using it mainly as a test instrument, spectrum Analyzer. 
I would like to try to use the receiver(s) as part of a receiver/transmitter configuration where the transmitter has its own DDS front end to a simple transmitter.  Completely separate receive/transmit controls with the possible exception of a pin diode mute to the duo.. (something like the MFJ-1708, but homebrewed).

Have any of you done this?

For the transmitter, I am NOT talking about simply using an exsiting transciever as the transmitter.  But it would work that way..

If you look at QRZ for W6JL and look at his rig.. he is using a completely separate receiver/transmitter config...  heck... I just answered my own question.. take a look.  
Instead of his homebrew Tayloe receiver I substitute the sdrplay.. heh heh...

I ramble.  If you have set up something like this I would be curious.

Thanks!
N1GMM
---------------------------------

I got a response pointing me to a video here:
   it is in Italian.. but you will get the idea.

The specs for the ELAD isolation switch is here: 


$102..

MUCH better specs than the MFJ unit.  and even costs less and better constructed...

Have Fun, Stay Safe and keep on the Sunny Side!

Guy

Re: USB Communation RXTX with PowerSDR on Win10

#88201

WSJT-X software tries to Transmit the RXTX start to output a RF signal to the antenna then immediately I get an error message from PowerSDR "USB Device Not Found (-1)" .
what could cause it to drop USB communation after PTT? I am driving the RXTX close to max power, but using IQTester app and CFGSDR utility the RXTX will drive close to 1W into a dummy 50 ohm load with no problem. Robert,

Has anything changed with the antenna or radio setup?
The symptoms you describe suggest RF getting into the USB line.
Seems unlikely with just one watt, how does it work with WSJT driving it but into the dummy load?

73 Alan G4ZFQ

USB Communation RXTX with PowerSDR on Win10

#88200

Has anyone seen problems with an Ensemble RXTX when using PowerSDR software running with Windows 10 commutating with the USB port. Specifically, when everything is setup correctly (say 20M FT8 14.074 MHz, soundcard and software) and waterfall shows FT8 signals received, then when PowerSDR Tune button is pressed of the WSJT-X software tries to Transmit the RXTX start to output a RF signal to the antenna then immediately I get an error message from PowerSDR "USB Device Not Found (-1)" .

This error (USB Not Found) would pop up every other time I was using the RXTX with PowerSDR and WSJT-X FT8 Digital Mode on 20 or 40M. When working I made lots of contacts using an End Feed Long wire antenna and a 1:9 Unun. For the last week the same configuration that had been successful fails every time. The RXTX USB connection seams to respond to all commands correctly except when PTT is activated.

Assuming the problem is with the RXTX, what could cause it to drop USB communation after PTT? I am driving the RXTX close to max power, but using IQTester app and CFGSDR utility the RXTX will drive close to 1W into a dummy 50 ohm load with no problem. It used to work and now it doesn't can any one help?

Robert, KI5HBO

Re: Looking for something to build and software to use

#88199

On 30/09/2020 18:07, David Matthews wrote:
What software should I be looking at?  I would prefer LinuxDavid

Works nicely with the Ensemble RXTX.

73
Nick

Re: Looking for something to build and software to use

#88198

I just finished building a Phaser FT8. Nice kit, great support. Puts out about 3 watts on 20 m. Check out the web site for Midnight Design Solutions. 

Bruce A. KF0ET

Sent from my not so smart iPhone

Show quoted text

On Sep 30, 2020, at 2:45 PM, David Matthews <n36078@...> wrote:

Thanks, I'll take a look at your page.  I would do another 6.3 but
Tony hasn't sold those for quite a few years.

Dave
W2IJL

On Wed, Sep 30, 2020 at 2:43 PM Alan G4ZFQ <alan4alan@...> wrote:


What software should I be looking at?  I would prefer Linux but I have
the laptop set up as dual boot and can use Windows if needed.  I
looked at FLDigi on the LinuxDave,

Something like an Ensemble or 6.3 is good.
Digi-modes, especially RX/TX really require a combination of software
connected by a Virtual sound utility.
My page for Windows and WSJT-X here

Similar is done in Linux but not described by me:-)

73 Alan G4ZFQ

Re: Looking for something to build and software to use

#88197

Dave,

There are quite a few choices.  These are only the ones I know about - several more are out there.  All of these are on groups.io to include assembly instructions if not on the website:

Multus SDR Proficio - multiband - HF - it is an SDR so no interface needed for digital modes other than Virtual sound utilities that Alan mentions.

QRP Labs QCX - single band-  but has other products as well such as the U3S which cover 630 M and 2200 M which the Softrock can also do with some modifications

Midnight Design Solutions Phaser - single band two frequency QRP specifically designed for digital - preprogrammed with FT8 and JS8 frequencies

WSJT-X runs on just about everything including Raspberry Pis

73,

Dave, W4VU

Re: Looking for something to build and software to use

#88196

Thanks, I'll take a look at your page.  I would do another 6.3 but
Tony hasn't sold those for quite a few years.

Dave
W2IJL

Show quoted text

On Wed, Sep 30, 2020 at 2:43 PM Alan G4ZFQ <alan4alan@...> wrote:


What software should I be looking at?  I would prefer Linux but I have
the laptop set up as dual boot and can use Windows if needed.  I
looked at FLDigi on the LinuxDave,

Something like an Ensemble or 6.3 is good.
Digi-modes, especially RX/TX really require a combination of software
connected by a Virtual sound utility.
My page for Windows and WSJT-X here

Similar is done in Linux but not described by me:-)

73 Alan G4ZFQ

Re: Looking for something to build and software to use

#88195

What software should I be looking at?  I would prefer Linux but I have
the laptop set up as dual boot and can use Windows if needed.  I
looked at FLDigi on the Linux Dave,

Something like an Ensemble or 6.3 is good.
Digi-modes, especially RX/TX really require a combination of software connected by a Virtual sound utility.
My page for Windows and WSJT-X here 
Similar is done in Linux but not described by me:-)

73 Alan G4ZFQ

Looking for something to build and software to use

#88194

I am looking to get back on the air and playing with QRP again.  I
have a Softrock 40 and someplace around here I have a mostly completed
mobo setup with my 6.3 on it.  What I would like is to build a
transceiver for either 20 or 40 mostly for the digital modes.

Way back when I was using Rocky with the 6.3.  I see that Rocky has
been updated to work with Win 10 but the only digital mode is PSK-31.

Besides the Ensemble RXTX are there any othersthat I should be looking
at?  My son suggested the Ubitx but that looks to be just a
screwdriver exercise to assemble.

What software should I be looking at?  I would prefer Linux but I have
the laptop set up as dual boot and can use Windows if needed.  I
looked at FLDigi on the Linux side but it doesn't really like my usb
sound devices.

Soldering and dealing with software are not a problem.

Dave
W2IJL

Re: RXTX Ensemble Build(s) project.

#88193

Hi Roger;
I have your document before me and I am putting together a BOM for the build of the 160-10 Meter Mods.
In your document you state: " iii)	replace the old filter with a set of switched or plug-in filters that will cover all bands. Andy, YL2QN, has designed and built a switched filter for his RXTX mod. "


For the External Filters
I have looked everywhere in the forum (its huge) for YL2QN's switched filter.  I would love to see what he built. (these (BP?)filters between the QSE mixer and driver...  Do you have a link?

I have your switched filter as well (the link to the 3 pole 6 Position Switch has expired) It actually pointed to a 1 pole 6 pos, 3 stack switch.. This is actually the external LPF.  These switches are pricey. Unless I wait for the slow boat from China... 

I read your Rationale as well about the filters...it is the QSE BP filter that has me a bit confused.. Do you have a design with different plug in filters?

I am enjoying this greatly.  Thank you again Roger..

PS.. I wonder why the 6.3 design with the plug in filters was discontinued by Tony.. perhaps I have not read enough..
PSS. Thanks for the patience for a VERY latecomer to use these Softrocks.. 

Guy

Re: RXTX Ensemble Build(s) project.

#88192

Guy,

Congratulations on completing the build and quick success! Nice work.

Re. the broadband version, someone who recently built one told me that he had used the supplied small transformer cores and fine wire and they worked fine on all bands. I had substituted larger cores and wire to make the winding easier for me. So if you love winding transformers, you get to have more fun with the next one. As for the order of build and testing, you can follow the same procedure as for your first one (rather than the procedure I suggested for modifying an existing standard build), just substituting the new parts as you go along.

73,
Roger

Show quoted text

On Sep 27, 2020, at 3:37 PM, Guy Mengel <guy@...> wrote:

Roger. Thank you for the encouragement. 
Just finished the 40/30/20 build. All went well. 950mw out first check. 
Pictures are here. Mostly old hat for most here. 
Next. The broadband rig. And then....thinking seriously about top band and below. After reading your materials.
..
Thanks again for the encouragement.  This kit is definitely not for the beginner. Indeed. 
I love the transformers. I love the fiddly stuff. 




73 
Guy N1gmm

Re: RXTX Ensemble Build(s) project.

#88191

Roger. Thank you for the encouragement. 
Just finished the 40/30/20 build. All went well. 950mw out first check. 
Pictures are here. Mostly old hat for most here. 
Next. The broadband rig. And then....thinking seriously about top band and below. After reading your materials.
..
Thanks again for the encouragement.  This kit is definitely not for the beginner. Indeed. 
I love the transformers. I love the fiddly stuff. 




73 
Guy N1gmm

Re: RXTX Ensemble Build(s) project.

#88190

Hello Guy,

Nice to hear about your project. Sounds like this will keep you occupied for a while an provide lots of enjoyment.

Your plan to build the first RXTX as designed sounds prudent. 

If you choose to build the 2nd unit for the 160-10m design, that should be quite straightforward for you after having done the first unit. Building the modified design, starting from a bare board, would involve very little more work than does the standard design.

I use my RXTX on CW. The latency is manageable, although not the experience of a conventional full break-in rig.

If you have any questions, problems, or suggestions for improvements, please let me know.

Roger

Show quoted text

On Sep 23, 2020, at 9:54 AM, Guy Mengel <guy@...> wrote:

All,
I have not seen much recent building on this site so I will start posting about the build(s) I am doing.  I built a softrock-40 many moons (years) ago and then gave it to someone.
I am interested in SDR's but dont have the $ to throw 3-10K into a QRO rig.  So, I spent (89x3 + $65) on 3 RXTX units, and one Ensemble II receiver.  I was (am) inspired by Roger's postings, and Brent Dewitt's Rig(s) [Dual RXTX in a single box].   I have started the build, and have the first RXTX communicating with the Computer and the SI570 generating squarewaves.   I am working on this as I have time. This Covid 19 Virus and the University I work at has my time all bollixed up.  Here are my ideas.
1. Build first RXTX unit and make sure it works as designed (80/40?) or ?
2. Build second unit, but broadbanded per Rogers multi-band rig.
3. Build third unit... as ?
4. The Receiver is for experimentation.

Much more fun than simply stuffing boards.. 
I am also building from scratch a tayloe modular unit like what you see on  including the tube amp..  Not very far along on this.. still putting schematics in the computer.

I am a CW guy but @ about 25wpm.. latency issues may creep up on me with SDR we will see.

I am interested also in modeling the filters that will be necessary with a VNWA3EC I have.  Along with a hacked specan using a RSPDUO with spectrum analyzer software.

Anyway.. hope to post a bunch and have fun.    Prelim pics here: (not much there yet!) 

73 Guy N1GMM. hope all are well! 