Date   
Re: Five Watt Amplifier times out

George Korper
 

Thank you Andy, i did forget to mention that!

It is a battery with solar and pretty constant at 13 volts when the amp is running. 
I keep a voltage meter on the system, which I watch as i'm using the amp. Most of the time the amp stays on when the 
WSPR comes on, but if the interval is long the amp must be switched on and off.

Re: Hints for winding T1 in QCXs

terryhugheskirkcudbrifght@...
 

hi all
i agree that it is best to start with mounting t1
i would add that it is best to mount all the toroids because you can then check for continuity ( and thus the solder joints)  if no other components are mounted.

terry gm4dso

Re: Hints for winding T1 in QCXs

Ted 2E0THH
 

I strongly second these comments from Reg.
Like most, I had never wound a torroid in my life before the QCX40 and I just followed the instructions, 8000+ kits speaks for itself.

Over the years I have had a great deal of experience working with military specs and manuals for kit costing several magnitudes beyond $49! The QSX manual would put many of those to shame.

73s Ted
2E0THH


On Mon, Aug 12, 2019 at 10:32 AM, R. Tyson wrote:
Hi all,
Just take the time to study the diagrams and the photos. Make sure you have got it clear in your mind - go over the diagrams until you are happy that you know how it is done. It's not difficult and is nothing to be scared of. Once you have it mentally sorted Just make sure you have the correct number of turns on.

The most fiddly part is getting all the wire ends into the correct holes and pulling them down so the toroid fits snugly on the board. Make sure you get a good solder joint on each wire end - it will save you fault finding later on ! I clean each wire end before fitting the coil to the board as well as leaving the soldering iron on for several seconds.

The 40 meter coil was fairly easy to get into place. I found the 20 meter coil more difficult. There are only 3 turns on each secondary winding (if my memory is correct) and these kept loosening up and moving each time I tried to get all the wire ends in place through the board....  persistence and several attempts won out in the end.

Regard the whole thing as an exercise in patience !

Reg        G4NFR 

Re: Hints for winding T1 in QCXs

R. Tyson
 

Hi all,
Just take the time to study the diagrams and the photos. Make sure you have got it clear in your mind - go over the diagrams until you are happy that you know how it is done. It's not difficult and is nothing to be scared of. Once you have it mentally sorted Just make sure you have the correct number of turns on.

The most fiddly part is getting all the wire ends into the correct holes and pulling them down so the toroid fits snugly on the board. Make sure you get a good solder joint on each wire end - it will save you fault finding later on ! I clean each wire end before fitting the coil to the board as well as leaving the soldering iron on for several seconds.

The 40 meter coil was fairly easy to get into place. I found the 20 meter coil more difficult. There are only 3 turns on each secondary winding (if my memory is correct) and these kept loosening up and moving each time I tried to get all the wire ends in place through the board....  persistence and several attempts won out in the end.

Regard the whole thing as an exercise in patience !

Reg        G4NFR 

QCX/QSX Elmering and Discussion

Ed Kwik
 

Hi Everyone!
AB8DF is inviting you to a scheduled Zoom meeting.

Please join us Monday August 12 at 7:00 PM EDT / 23:00 UTC for our next QRP Labs QCX/QSX transceiver Chat where the main topics will be the QRP Labs QCX single band CW transceiver and the soon to be released QSX multiband
CW/SSB transceiver. It's fun, it's easy, and it's free. You only need a computer, a smart phone, or a tablet that can connect to the Internet. OR if you can't be close to any of those you can join by audio with any standard phone. Just follow the directions below.

No software needs be loaded or installed.

MIQRP CLUB is inviting you to a scheduled Zoom meeting.

Topic: MIQRP QCX/QSX discussion
Time: Aug 12, 2019 7:00 PM Eastern Time (US and Canada)

Join Zoom Meeting
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Re: Five Watt Amplifier times out

M0RON
 

Hi George ,
you don't say what your 12v power source is, I'd suspect this first. Try using a battery instead. 
Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.

Re: Hints for winding T1 in QCXs

MrMSterner .
 

Good evening and thank's for letting me join the group extended with a lot of learning and joy.

I'm swedish in the middle age and just received my QCX CW 20m kit and following the group minutiously. However the T1 seems to be the "big challange".

I'm 43 yrs and when I was younger I completed my technician studies at highschool, after that I went over to IT (as many of you out there) and for today spent almost 19yrs at a Canadian company.

As a assembly constructor of the QCX20 I will start with the inventory and then assembly the  T1 first.

From my sight the suggested plan to follow the winding of S3 as a very good first step, solder it to the PCB and then continue the rest of windings of T1. I don't know who sent this picture but (frequency band dependent) allignment, left versus right hand in the 4 parts of winding, looks good. I also agree that the manual is a little bit un-clear in this part.

I hope to hear from you all soon in the future, perheps in a contest.

73
/s0Michael


On Sun, Aug 11, 2019, 22:13 dkwflight <dkwflight@...> wrote:
Hi
After my limited experience winding T1 I think I will try to color code the different sections along with your suggestion.
Thanks
Dennis
AG4TD

Five Watt Amplifier times out

George Korper
 

Hi,
I am using the five watt amplifier at times of poor propagation, and my 200 MW
WSPR is not getting spots. to test the difference high power makes. The amp is working perfectly,
but when there is a long interval between transmissions I sometimes have to switch the 12 volt supply on and off
and restart the amp. The bias is set just below full power. Peak power is 6 or 7 watts and I set it to five,
I don't want to increase the interval on the SotaBeam WSPR and hog the freq. Any ideas? 
Thanks and 73
K3GK

Re: SSB RX on QCX

Hans Summers
 

Hi Jim

Pre-QCX... my receiver (homebrew, see http://hanssummers.com/polyphase was also on LSB (in QCX called CW-R). It was all I knew (as I don't own any commercial HF radios and never have). I was surprised to learn that by convention, CW mode settings on amateur transceivers are USB. It took quite some effort to re-train my habits!

73 Hans G0UPL 


On Sun, Aug 11, 2019, 23:27 James Daldry W4JED <jim@...> wrote:

Hi, Hans

I switched my QCX 40 to CW-R so the CW pitch would go down when I tuned the radio down-frequency. Just personal preference. Makes the radio feel nicer to my ears.

73

Jim W4JED

On 8/10/19 3:30 PM, Hans Summers wrote:
Hi Guido

Was not ware of this feature, and actually it has never came to mind that stations could come back on the CW-L band ...
I guess CW/CW-L switching is used when QRP stations are using direct conversion receiver and unaware of the side they use? is it that?

Transmit is ALWAYS on exactly the frequency shown on the display. The CW/CW-R (for CW-Reverse) setting only affects which sideband the receiver listens to. So, whether the LO is above (CW/USB) or below (CW-R/LSB) the operating frequency. 

I can't see how it could be related to the station at the other end being direct conversion and not knowing what side he is on - because the setting CW/CW-R only affects what you hear. Not what you transmit. So it can't affect him at his end. 

I've never ever switched on CW-R. I've never found a use for it. I implemented it because other radios do and because it is trivially easy to implement (being just a matter of the way the Si5351A is configured whether the phase shift is + or - 90 degrees). To change from one to the other just requires enabling the invert on one of the Si5351A quadrature outputs - thereby applying a 180-degree phase shift to it and bringing the total phase shift to 270 degrees. Or -90 degrees, equivalently. 

I suppose one conceivable use of it could be where there is a very very strong station on LSB which is interfering with your wanted weak signal CW station on USB. Maybe this could happen in a contest situation, I don't know. I am not good enough at this whole radio thing, to dare participate in contests. Anyway the unwanted sideband rejection in QCX is extremely good; so far I have never heard a station on the unwanted (rejected) sideband, let alone heard one at a strong enough level that it was annoying enough to go into the menu, switch to CW-R and tune 1.4kHz the other side of my wanted station! 

73 Hans G0UPL

Re: SSB RX on QCX

James Daldry W4JED
 

Hi, Hans

I switched my QCX 40 to CW-R so the CW pitch would go down when I tuned the radio down-frequency. Just personal preference. Makes the radio feel nicer to my ears.

73

Jim W4JED

On 8/10/19 3:30 PM, Hans Summers wrote:
Hi Guido

Was not ware of this feature, and actually it has never came to mind that stations could come back on the CW-L band ...
I guess CW/CW-L switching is used when QRP stations are using direct conversion receiver and unaware of the side they use? is it that?

Transmit is ALWAYS on exactly the frequency shown on the display. The CW/CW-R (for CW-Reverse) setting only affects which sideband the receiver listens to. So, whether the LO is above (CW/USB) or below (CW-R/LSB) the operating frequency. 

I can't see how it could be related to the station at the other end being direct conversion and not knowing what side he is on - because the setting CW/CW-R only affects what you hear. Not what you transmit. So it can't affect him at his end. 

I've never ever switched on CW-R. I've never found a use for it. I implemented it because other radios do and because it is trivially easy to implement (being just a matter of the way the Si5351A is configured whether the phase shift is + or - 90 degrees). To change from one to the other just requires enabling the invert on one of the Si5351A quadrature outputs - thereby applying a 180-degree phase shift to it and bringing the total phase shift to 270 degrees. Or -90 degrees, equivalently. 

I suppose one conceivable use of it could be where there is a very very strong station on LSB which is interfering with your wanted weak signal CW station on USB. Maybe this could happen in a contest situation, I don't know. I am not good enough at this whole radio thing, to dare participate in contests. Anyway the unwanted sideband rejection in QCX is extremely good; so far I have never heard a station on the unwanted (rejected) sideband, let alone heard one at a strong enough level that it was annoying enough to go into the menu, switch to CW-R and tune 1.4kHz the other side of my wanted station! 

73 Hans G0UPL

Re: Hints for winding T1 in QCXs

dkwflight
 

Hi
After my limited experience winding T1 I think I will try to color code the different sections along with your suggestion.
Thanks
Dennis
AG4TD

Re: QCX-30

dmason@...
 

I will take that if it’s still available Jack.

Thanks,
Dale, W9ESE

Re: ProgRock not working #progrock

Robin Midgett
 

Great news..at least as far as working on frequency...I've finally had/taken time to build the QLG1 kit & connect it to my ProgRock. Once the QLG1 locked on GPS satellites & the 1PPS started, the ProgRock locked onto the desired frequency of 16.686666 MHz. and so far seems stable. 
Previously, using the Trimble T GPS module and a homebrew 555 based pulse stretcher to give a 116mS long 1PPS, I had a constant 18Hz. frequency discrepancy. In that case I fooled the ProgRock onto the desired frequency by programming register 8 18 Hz. higher than desired & setting register 3=0. Under those conditions the ProgRock would be stable and on frequency over a period of days. I"m still curious to experiment with the Trimble T and see if I can duplicate the reliability that comes with the QLG1, but for now I need to move forward with putting the propagation beacon, which is the basis for the project, on the air.
I'll see how reliable the ProgRock is over the next few days with the QLG1 supplying the 1PPS.

Robin Midgett K4IDC


On Sun, Jul 28, 2019 at 6:09 AM <mike@...> wrote:
I no longer have a trimble 't' so I can't test it, but yes, dats da sucker
afik.


On 27 Jul 2019 at 14:06, Robin Midgett wrote:

> Hey Mike,
> Is the software at the URL below the correct software for the Trimble T?
>
> Robin Midgett K4IDC
>
>
> On Mon, Jul 22, 2019 at 8:30 AM Robin Midgett <K4IDC@...> wrote:
>
> > Mike,
> > Is this the software you are recommending?
> >
> >
> http://trl.trimble.com/docushare/dsweb/Get/Document-484972/TrimbleStudio.exe
> >
> > Robin Midgett K4IDC
> >
> >
> > On Mon, Jul 22, 2019 at 8:16 AM Robin Midgett <K4IDC@...> wrote:
> >
> >> GM Mike,
> >> Ok, I'll check it out. Thanks much for that insight.
> >> My QLG-1 arrived Saturday, so that's 2 experiments I can perform soon.
> >>
> >> When you say the QLG-1 didn't change anything for you, are you saying
> >> your ProgRock worked properly with the QLG-1 and another GPS, or that it
> >> didn't work properly & by attaching a QLG-1 nothing changed, bringing
> the
> >> need for other action?
> >>
> >> Robin Midgett K4IDC
> >>
> >>
> >> On Mon, Jul 22, 2019 at 2:58 AM <mike@...> wrote:
> >>
> >>> Gm Robin..
> >>>
> >>> On 21 Jul 2019 at 22:56, Robin Midgett wrote:
> >>>
> >>> > How would triggering on an unrelated & unsynchronized 1PPS help?
> >>> It would confirm that the 1pps under test is not at fault. - some
> >>> Trimble T's
> >>> that are sourced in china are counterfeit and not actually Trimble T's
> >>> The same with some U-Blox engines.
> >>>
> >>> > I don't have Trimble's propriortized software, nor am I connected to
> >>> the
> >>> > GPS with a computer.
> >>> Then get it, from Trimbles website. Connect a computer , ttl serial, to
> >>> your
> >>> Trimble T and change the 1pps pulse duration to something appropriate
> >>> and
> >>> write it to the GPS's Eeprom. Using the software you can also check
> that
> >>> the
> >>> claimed defaults are set correctly.
> >>>
> >>> Remove the possible source of latency and see if the issue remains.
> >>>
> >>> I have seen many similar conversations on the list. The usual answer
> >>> 'get a
> >>> QLG-1' does'nt answer why one 5v TTL 1pps works and another,
> >>> functionally
> >>> identical 5v TTL 1pps does'nt - why not borrow or buy a QLG-1 and see
> if
> >>> it
> >>> actually changes anything. It did'nt for me.
> >>>
> >>>
> >>>
>


Re: ProgRock not working #progrock

Robin Midgett
 

Great news..at least as far as working on frequency...I've finally had/taken time to build the QLG1 kit & connect it to my ProgRock. Once the QLG1 locked on GPS satellites & the 1PPS started, the ProgRock locked onto the desired frequency of 16.686666 MHz. and so far seems stable. 
Previously, using the Trimble T GPS module and a homebrew 555 based pulse stretcher to give a 116mS long 1PPS, I had a constant 18Hz. frequency discrepancy. In that case I fooled the ProgRock onto the desired frequency by programming register 8 18 Hz. higher than desired & setting register 3=0. Under those conditions the ProgRock would be stable and on frequency over a period of days. I"m still curious to experiment with the Trimble T and see if I can duplicate the reliability that comes with the QLG1, but for now I need to move forward with putting the propagation beacon, which is the basis for the project, on the air.
I'll see how reliable the ProgRock is over the next few days with the QLG1 supplying the 1PPS.
Thanks,
Robin Midgett K4IDC


On Tue, Jul 30, 2019 at 10:38 AM Alan G4ZFQ <alan4alan@...> wrote:
> Is it easy enough for you to check the value of register 2 in your
> ProgRocks when they're on frequency, and then again when they're off
> frequency by whatever error you're seeing?

Robin,

I've never been too bothered about register 2, it's either set for
accuracy if there is no GPS or it sets itself. When setting manually
I've not noticed any non-linearity.
The attached picture taken some time ago shows my Progrock set at
14.996MHz from a cold start. As it starts about 2KHz off I guess
register 2 was about 4KHz away from correct.
As you see it rapidly corrects and settles 2Hz lower than the GPS
derived marker (Neo 7) at 14.996MHz. (Bottom spectrum, RX not quite
accurate) Looks like register 3 is 0?
If I set register 2 I can make it more accurate but if the GPS is
connected it will settle 2Hz low and stay there. I have done more
extended tests to confirm that within a few tenths of Hz.
A restart will then be close to the wanted frequency.
I suspect this test was with a 26MHz TCXO which might explain why the
frequency settles 2Hz low. All my available synth boards are now
non-standard, I cannot repeat this with a standard crystal but it does
show how the control works and that it settles as near as I can see at a
constant frequency.
I'm not sure what GPS I used, possibly a Neo-7, maybe an old Garmin.
I've not got a QLG1.

> I can set reg. 2 to a proper value to give the correct output frequency,
> set reg. 3 to something very high (30),

Why 30? I would think 5 was as much as anybody would want, zero if you
are looking for real precision.
I wish I could help further.

73 Alan G4ZFQ




Re: Hints for winding T1 in QCXs

Joe Cotton
 

Looking over my previous post for the 20th time, I think that I need to add this.

Winding the secondary 3 over 180 degrees of the toroid,  Point a short lead down as you hold the toroid and the wire, wind the long end of the wire up, over the top, into the toroid, and under.  Continue in this direction. When finished winding, the short end that you started with will go in hole 1, and the long end will go in hole 2.    

The purpose of this instruction is to get the winding direction correct. 

It turns out (no pun intended) that all windings start out with a short end pointing down, held close to the toroid on the outside of the toroid.  Then the windings go up, over the top, inside the toroid, and underneath, coming back up on the outside of the toroid, on the right side of the previous turn, (with the turn facing you).  The turns will continue in a counter-clockwise direction, looking from the top. 

Joe W3TTT  

QCX-30

Jack Hubbard <ni8njack@...>
 

Free to good home, non operating QCX-30.  You pay shipping.  Also a printed assembly/operating manual in a 3 ring binder.  ni8njack@...

IC10 short? No audio

Ashdee 9W8ASH
 

Greetings all,

Quick disclaimer. I'm by all means a non-technical person. I assembled only by the manual, and when in trouble (like wrongly assembled parts, which was half a dozen) I watched youtube build videos to help me out. I do not know how to test/troubleshoot that well as anything beyond the manual is out of my field.

I've been scouring this forum to find if anyone ever had a problem with audio and/or IC10. I had audio previously for maybe 5 minutes (which enabled me to align my QCX) but after that audio just went dead. Leaving it off for several hours will enable me to get audio when starting up, but again, for maybe 3-5 minutes.

For the past few days I've doing continuity checks, checking for any cold joints, bridges, etc. I've resoldered any dodgy looking pads.

I moved onto checking voltages of all the items as per the manual, since thats the only thing I have. Of all that was checked, only IC10 stood out, with measurements as per below using the built in QCX DVM feature:

IC10
Pin 1 - 11.18
Pin 2 - 11.18
Pin 3 - 11.18
Pin 4 - 0.00
Pin 5 - 3.03
Pin 6 - 2.26
Pin 7 - 11.16
Pin 8 - 11.96

Could this be the problem? I also did a quick check on C51 with an external multimeter, the readings weren't the same with C24, C37 and C38 (all are the same 10uf capacitor) and is constantly fluctuating (C24, C37 and C38 did not).

Any comments is highly appreciate.

73
Ashdee
9W8ASH

Re: Hints for winding T1 in QCXs

Joe Cotton
 

Hi Jim
Great hint for winding T1 for the QCX. The T1 winding step may be the hardest part of the whole megilla. 
The point that you make to wind the secondary winding 3 first and to mount the T1 as the first step are great ideas. 
However, your description of winding the primary and the secondary 1 and secondary 2 are not clear to me.  Allow me to say it in my own words and see if I understand you correctly. 

Step 1.  Wind secondary 3 over half of the toroid.  Solder it in holes 1 and 2, leaving room between the toroid and the board for wires (to come). 
Step 2.  Take about two inches of wire, tin one end, solder to hole 5.  This wire is standing straight up.
Step 3.  Bend the wire over the top of the toroid, then down into the toroid, and then underneath the toroid, coming out between hole 5 and hole 1. 
Step 4   Repeat step 3, two more times.
Step 5.  You should have a short length of wire left.  Bend this over the top of the toroid, and down into hole 6. Solder hole 6.

Step 6,  Repeat steps 2 through 5, for holes 3 and 4.  The first winding should come out between holes 3 and 5 in step 3.
Step 7.  Repeat steps 2 through 5, for holes 7 and 8.  The first winding should come out between holes 7 and 3 in step 3.

It's the step 3 which I want to get correct, and leave no doubt exactly what to do!  Do I have step 3 correct? I think that the windings all need to be in the correct direction. Do I have it correct?

thanks
Joe W3TTT

Re: SSB RX on QCX

ajparent1/KB1GMX
 

CW-R is a good feature for SSB RX on 40m...

The best mod for the filter is leave it stock and duplicate it for SSB bandwidth
as its only two opamp packages and a few parts.  Then a switch selecting the
output of one or the other gives excellent CW and SSB.  Would not take much
of a board to make one or just dead bug it.

Allison

Re: Using an SDR with QCX

Hans Summers
 

Hi Bob

Gain before selectivity reduces intermodulation performance. IP3, dynamic range, linearity. 

In the old days mixers were lossy and it was necessary to have gain ahead of the mixer (the RF amp stage), otherwise overall receiver sensitivity would not be good enough. I think RF amps ahead of the selectivity were a necessary evil, not a desirable feature. 

Nowadays the switching type mixers e.g. Quadrature Sampling Detector (as used in QCX and the Receiver module) have very low insertion loss and one of the benefits to come out of that, is no need for the RF amplifier. The QSD also has very high IP3 and not putting an RF amp in front means the high IP3 of the mixer (and therefore good signal handling of the whole radio) is preserved. 

VHF still usually needs RF amps because band noise levels are so low. But anyway at VHF demands on receiver are less than on crowded HF bands.

Superhet receivers have other additional problems, like mixing products (birdies) requiring good attention to shielding and filtering throughout the radio. To get general coverage HF and to avoid the difficulties of choosing an IF which doesn't adversely impact some amateur band or another, dual conversion is necessary, using a first IF of something some way above HF e.g. 45MHz. But double conversion multiplies up on all the problems...

Everything is tradeoffs but I think generally with modern components, the ability to get high performance at HF using simple direct conversion designs, easy to align and use, has been a very beneficial development. I'm not a superhet fan. Not that I'd never build one... but if doing so I think lots if filtering and shielding are in order... and probably much harder to get the same high level of performance. 

73 Hans G0UPL 






On Sun, Aug 11, 2019, 01:55 Bob Macklin <macklinbob@...> wrote:
I come from the time where the superhet was the design of choice.
 
Good ones had an RF amp. Better ones had 2 RF amps.
 
A single IF amp was most common. But better receivers has two IF amps.
 
Then there were double conversion receivers.
 
Why not a superhet followed by a quadreature IF second stage. Why do we want all the gain after the quaderature detector?
 
BTW:
There are 1836KHz crystals and oscillaord that would allow building a Taylor detector behind a 455KHz IF.
 
Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
----- Original Message -----
Sent: Saturday, August 10, 2019 3:32 PM
Subject: Re: [QRPLabs] Using an SDR with QCX

OK , its a problem with all mixers, there are not that are immune totally.

IF you run a switching mixer and the control lines and the control source (this case 5351)
are totally shielded.... guess what you still get RF at the input port from the switching
action and incidental leakage inside the IC.  Happens with DBMs too.  Even the best
mixers are rarely more than 50db below the RF drive. considering most have a drive
level in the 7-20dBm range there will be some signal in the microwatt region getting
to the antenna.

What the solution?

There are two common ones.

Use a common base of common gate RF amplifier before the mixer (between
mixer and antenna) as this type of amplifier has a fairly high reverse transfer
(S21) meaning signals at the output have a hard time getting to the input.

The other is superhet where the input filter attenuates the signal from the mixer
at the RF+IF (or RF-if).  The filter passes 7mhz but not the other possible
frequencies.

So most of the DC RX (be they SDR or analog) radio have this, unless they
have an RF amp of low gain but high isolation.  Even then some amount of
LO is radiated unless one has a well laid out enclosure that provides good
shielding.

With all that its touch to have a radio near another radio and not expect
to find the first radios receivers emissions.

However If one knows where to look (frequency) you can easily track 
where the RX is (both location and frequency!).

IF you want to use a SDR for RX build a TX  to match that radio.
For CW that is simple.

Allison