Warren,
I have to do the same.

I've got it working now, it looks like I had a bad connection on one of the
audio cables.  It was a strange fault and seemed to cure its self when I ran
Rocky and then WSPR 2.1 again.

Regards
Colin G1IVG.

--- In softrock40@yahoogroups.com, "warrenallgyer" <allgyer@...> wrote:
>
> Hi Colin
>
> I find when I start WSPR I often must de-select then re-select the band that I
desire, even if it is sitting on the proper band at startup. Similarly, I select
both audio interfaces on the Station Parameters panel, even if they are
indicating the proper ones at startup.
>
> For some reason these settings do not seem to survive from previous sessions
for me and I have just settled in this habit rather than investigating why.
>
> Warren Allgyer - W8TOD
>
> --- In softrock40@yahoogroups.com, "G1IVG" <g1ivg@> wrote:
> >
> > Help!!!
> >
> > I have been using my Softrock Ensemble RXTX successfully for over a year and
have made many contacts on SSB using PowerSDR.  However over the last few days
I've been trying to get it working on WSPR using WSPR 2.1.  I'm receiving and
decoding really well, but for some reason my Softrock Ensemble RXTX doesn't want
to transmit any RF even though the WSPR software displays the yellow TX box on
the bottom right of the screen.
> >
> > The problem is as if there is no PC generated audio coming out of the Delta
44 into the Softrock Ensemble RXTX.
> >
> > My WSPR setup is as follows:
> >
> > PC  : Windows 7 (32bit)
> > RXTX  : Softrock Ensemble RXTX (40m, 30m & 20m)
> > Soundcard : Delta 44 with KB9YIG's Interface board.
> > Software : WSPR 2.1
> >
> > I have the TX fraction set at 20 on the slider control and even though the
software looks as if the radio is transmitting I get no RF detected on my RF
power meter.  But with other SDR software when used on SSB I get a good clean 1w
of RF out of the radio.  The problem only seems to be when using WSPR when it
uses the Line In jack as opposed to the MIC In which is used on SSB.
> >
> > I must be missing something obvious, but can't seem to put my finger on what
the problem is.
> >
> > Any help greatly appreciated.
> >
> > 73 de Colin G1IVG
> >
>

Thanks for the tip Tim, I have also changed the default startup frequency now.

73 de Colin G1IVG

--- In softrock40@yahoogroups.com, "KQ8M" <kq8m@...> wrote:
>
> Warren,
>
>
>
> Unless you set the SI570 to default to the frequency you start WSPR on then it
goes to the 570 default. WSPR Does not send the
> frequency to the ensemble on startup.
>
>
>
> Tim Herrick, KQ8M
>
> Charter Member North Coast Contesters
>
> kq8m@...
>
>
>
> AR-Cluster V6 kq8m.no-ip.org
>
> User Ports: 23, 7373  with local skimmer, 7374 without local skimmer
>
> Server Ports: V6 3607, V4 Active 3605, V4 Passive 3606
>
>
>
> From: softrock40@yahoogroups.com [mailto:softrock40@yahoogroups.com] On Behalf
Of warrenallgyer
> Sent: Wednesday, February 20, 2013 6:06 PM
> To: softrock40@yahoogroups.com
> Subject: [softrock40] Re: WSPR TX problem on Ensemble RXTX with Delta 44 **
Help **
>
>
>
>
>
> Hi Colin
>
> I find when I start WSPR I often must de-select then re-select the band that I
desire, even if it is sitting on the proper band at
> startup. Similarly, I select both audio interfaces on the Station Parameters
panel, even if they are indicating the proper ones at
> startup.
>
> For some reason these settings do not seem to survive from previous sessions
for me and I have just settled in this habit rather
> than investigating why.
>
> Warren Allgyer - W8TOD
>
> --- In softrock40@yahoogroups.com <mailto:softrock40%40yahoogroups.com> ,
"G1IVG" wrote:
> >
> > Help!!!
> >
> > I have been using my Softrock Ensemble RXTX successfully for over a year and
have made many contacts on SSB using PowerSDR.
> However over the last few days I've been trying to get it working on WSPR
using WSPR 2.1. I'm receiving and decoding really well,
> but for some reason my Softrock Ensemble RXTX doesn't want to transmit any RF
even though the WSPR software displays the yellow TX
> box on the bottom right of the screen.
> >
> > The problem is as if there is no PC generated audio coming out of the Delta
44 into the Softrock Ensemble RXTX.
> >
> > My WSPR setup is as follows:
> >
> > PC : Windows 7 (32bit)
> > RXTX : Softrock Ensemble RXTX (40m, 30m & 20m)
> > Soundcard : Delta 44 with KB9YIG's Interface board.
> > Software : WSPR 2.1
> >
> > I have the TX fraction set at 20 on the slider control and even though the
software looks as if the radio is transmitting I get no
> RF detected on my RF power meter. But with other SDR software when used on SSB
I get a good clean 1w of RF out of the radio. The
> problem only seems to be when using WSPR when it uses the Line In jack as
opposed to the MIC In which is used on SSB.
> >
> > I must be missing something obvious, but can't seem to put my finger on what
the problem is.
> >
> > Any help greatly appreciated.
> >
> > 73 de Colin G1IVG
> >
>

Alan,

That must have been the problem.  All test points suggested the PTT was working
well.  However with no RF output detected.  I then used Rocky on CW for a bit
and that worked fine, I then returned to WSPR 2.1 and for some reason the
Ensemble started transmitting as it should.  I must have disturbed a bad
connection some how.

Thanks for all the help you and others give on this group.

Regards
Colin G1IVG

--- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
>
>
> ----- Original Message -----
> From: "warren
> Subject: [softrock40] Re: WSPR TX problem on Ensemble RXTX with Delta 44 **
Help **
>
>
> >
> > I find when I start WSPR I often must de-select then re-select the band that
I desire, even if it is sitting on the proper band at
> > startup.
>
>
> Yes, there are two ways of looking at this. Joe decided to leave it for the
operator to set at startup.
>
> The problem with Softrocks is that there is no frequency display and no easy
way of telling if it has been set to TX unless a LED
> has been fitted.
>
> Colin, Have you checked whether there is audio going into the Softrock?
>
> >Similarly, I select both audio interfaces on the Station Parameters panel,
even if they are indicating the proper ones at startup.
> >
>
> The usual reason is that Windows re-numbers audio devices when USB ones are
added or removed.
>
> 73 Alan G4ZFQ
>

Hi Fred

Picking a few nits here:

1) All transmissions are one way.
2) No WSPR is 24 hours a day. Even people who transmit at 100% (and almost no
one does this) transmit on approximately 1:50 cycles with at least 8 seconds of
rest. Most transmit at 20-30%, meaning 70-80% of the time the station is NOT
transmitting.
3) All valid WSPR transmissions are confined to a 200 Hz allocation by custom on
each band. On 40 meters this is 7040000 to 7040200.
4) WSPR users who cannot hit this allocation do not transmit for long because no
one will spot them.
5) No one is telling you not to transmit some other mode in this 200 Hz band. We
would all appreciate it if you did not but that band is open to do what you
wish.
6) I don't think the loss of 200 Hz is significant to QRP operators who respect
the custom. But that is my opinion.

I think you may have a point on "unattended operation" but I don't think there
is anything in the rules prohibiting WSPR type transmissions. And who among us
does "unattended operation"?...... well.... uh..... OK, I don't want to go
there.

:-)

Warren Allgyer - W8TOD



--- In softrock40@yahoogroups.com, Fred Moore <fred@...> wrote:
>
> Slightly off topic, but since we seem to have many WSPR ops here.  I notice
> a question on wsprnet.org some time ago and have not found the answer
> myself:
>
> <quote> I can't find a spot in the FCC rules that permits WSPR. Part
> 97.111(b) defines a list of permitted, short, one way transmissions. WSPR
> does not appear to fit the list because it is a list of "short"
> transmissions.
> Part 97.203 addresses beacons and permitted beacon frequencies. According
> to this paragraph, no beacons are permitted below 28.2 MHz.
> What an I missing and what loophole allows WSPR transmissions 24 hours per
> day?"
> </quote>
>
> I bring this up because I noticed that everyday the background on the water
> fall on .40 gets whiter and whiter from this type of 24 hour a day
> activity.  I am really wondering what the answer to this question is.   Not
> attacking anyone, just wonder about this activity?.. I also get concerned
> over the loss of a broad range of QRP frequencies, as many can't seem to
> get exactly on .40.  Can anyone enlighten me, off list is also okay if you
> don't want to clutter up the list..  fred@...
> Regards.. Fred
>
>
> --
> *Fred Moore*
> *Ham Radio:  WD8KNI
> *
> *Email: fred@...*
> *Cell: 321-217-8699*
>

----- Original Message -----
Subject: Re: [softrock40] Re: WSPR TX problem on Ensemble RXTX with Delta 44 **
Help **


> Slightly off topic, but since we seem to have many WSPR ops here.  I notice
> a question on wsprnet.org some time ago and have not found the answer
> myself:
>

Fred,

I think WSPR is in a grey (gray) area for most amateur regulations. Personally I
look at it as a "CQ" for a reply via the internet.
That is not unusual nowadays with internet gateways. The word beacon should be
avoided, at least by users of the mode!
200Hz is not a lot, no-one will operate outside this range for long, there is no
point they get no replies. And that 200Hz is
occupied by a fair number of operators, I see over 70 on 20m at the moment. 80
on 30m.
Yes, there is sometimes a shortage of space but I wonder what other mode has
that sort of occupancy in 200Hz?

.40? Where do you mean?

73 Alan G4ZFQ


> <quote> I can't find a spot in the FCC rules that permits WSPR. Part
> 97.111(b) defines a list of permitted, short, one way transmissions. WSPR
> does not appear to fit the list because it is a list of "short"
> transmissions.
> Part 97.203 addresses beacons and permitted beacon frequencies. According
> to this paragraph, no beacons are permitted below 28.2 MHz.
> What an I missing and what loophole allows WSPR transmissions 24 hours per
> day?"
> </quote>
>
> I bring this up because I noticed that everyday the background on the water
> fall on .40 gets whiter and whiter from this type of 24 hour a day
> activity.  I am really wondering what the answer to this question is.   Not
> attacking anyone, just wonder about this activity?.. I also get concerned
> over the loss of a broad range of QRP frequencies, as many can't seem to
> get exactly on .40.

I have for sale or trade a built Ensemble RXTX that was built by TJ W0EA for me.
I have done nothing with it and i have now turned my interests toward the
Arduino. I guess I have over a hundred dollars in it with purchase price and
builder fees.

I hope it ok to list it for sale here. I will send pic via my iPone to anyone
interested. At any rate reply off line please. Feel free to text me at 3 one
eight two zero 8 four.   One.   Four 5.

Thanks 72/73 John NS5Z

Actually an excellent point about rockbound QRP operations. I have one of those
myself. I would not mind moving the 40 meter WSPR a few KHz.

Warren Allgyer - W8TOD

--- In softrock40@yahoogroups.com, John Greusel <greusel@...> wrote:
>
> Fred,
>
> That's a good point for being protective of  7.040 for rock bound QRP
activities. I would suggest that you could suggest an alternative spot to Joe
and the WSPR community and it might have some effect. It's not such a large
group that your voice wouldn't be heard.
>
> John
> KC9OJV
>  
>
>
>
> ________________________________
>  From: Fred Moore <fred@...>
> To: softrock40@yahoogroups.com
> Sent: Saturday, February 23, 2013 10:29 AM
> Subject: Re: [softrock40] Re: WSPR TX problem on Ensemble RXTX with Delta 44
** Help **
>
>
>  
> John, thanks for the reply, and yes I have been on WSPR and have used it to
test propagation, and antennas. I have no objection to the mode or the
technology, I actually use digital modes quite often here. 
>
> I have several ham friends here that are heavily into that mode.  From
listening to them, and monitoring the local 2 meter repeater they just let it
run, every few days sometimes weeks, they check and see where there signals were
heard, than have a top dog discussion.  I can absolutely assure you that among
them and among most hams using this mode, that absolutely nothing is being done
as a study, no correlation is being done with solar, or anything else.  
>
> I also have monitored more than several hams on other forums discussing the
equipment required to run QRO for this mode,  just to say that their signals
are showing up when others are not. One recently was asking what the maximum
current he could run on an 8877 for WSPR, he didn't even understand the duty
cycle, intent, or use of the mode.  I queried why he would want to do that, his
commented that I obviously don't understand "Top Gun", It seems like it is
becoming more and more like a DX contest with some of these folks.  
>
> One such station on the other side of Orlando was splattering all over the
lower portion of 40 meters, about 50 miles from me last week.
>
> I full agree with you on FCC authority, and different rules.  I also agree
with you and others that this is a narrow frequency mode, when used
properly.  
>
> As for QRP being impacted I can not agree, until recently multiple thousands
of QRP radio's were rockbound and sold on 7.040.  These rockbound radios are
most times almost unusable for QRP, especially QRP/DX.  
>
> While testing antennas, equipment and propagation, and what ever you want to
know are very valid reason to run WSPR, these guys are not playing nice.  If my
small sample of this type of ham activity is confined to Orlando, I can't
imagine how much when the scope is moved worldwide.  My concern is that it
could grow like government, unchecked, and costly to the ham community.
>
> I have also come to the conclusion that I have no need to run this mode to
determine propagation,  I just look at the maps and let the other 20 thousand
people tell me what I need to know.
>
> Thanks for the informative discussion.. Regards..  Fred
>
> On Sat, Feb 23, 2013 at 8:59 AM, John Greusel <greusel@...> wrote:
>
>
> > 
> >Fred,
> >
> >
> >I agree that WSPR is not permitted as a beacon below 10 meters in the US and
when I use WSPR I try to not run my station without "operator control."  Even
J-65 which is a true two way event invites users to walk away while transmitting
because of the duration of time segments intrinsic to that mode. I would also
say that the FCC has no authority outside the US and many WSPR users would be
bound by differing rules. I've reminded several hams that running a "beacon"
with WSPR on 20 or 40 meters is not permitted in the US. I've also found that
some hams in the US don't know that beacons aren't allowed below 10 meters. WSPR
has made a beacon like function available to many now and some misuse is to be
expected. Where I disagree is that digital or QRP modes are seriously impacted
by the great interest in WSPR- it's a pretty narrow portion and much of those
slices are on bands that don't have much use.
> >Have you tried WSPR? It's really a great study in propagation and low power
levels. Everyone could learn something from it.
> >
> >
> >73's
> >John
> >KC9OJV
> > 
> >
> >
> >
> >
> >________________________________
> > From: Fred Moore <fred@...>
> >To: softrock40@yahoogroups.com
> >Sent: Saturday, February 23, 2013 6:06 AM
> >
> >Subject: Re: [softrock40] Re: WSPR TX problem on Ensemble RXTX with Delta 44
** Help **
> >
> >
> > 
> >Slightly off topic, but since we seem to have many WSPR ops here.  I notice
a question on wsprnet.org some time ago and have not found the answer myself:
> >
> >
> ><quote> I can't find a spot in the FCC rules that permits WSPR. Part
97.111(b) defines a list of permitted, short, one way transmissions. WSPR does
not appear to fit the list because it is a list of "short" transmissions.
> >Part 97.203 addresses beacons and permitted beacon frequencies. According to
this paragraph, no beacons are permitted below 28.2 MHz.
> >What an I missing and what loophole allows WSPR transmissions 24 hours per
day?"
> ></quote>
> >
> >
> >I bring this up because I noticed that everyday the background on the water
fall on .40 gets whiter and whiter from this type of 24 hour a day activity.  I
am really wondering what the answer to this question is.   Not attacking
anyone, just wonder about this activity?.. I also get concerned over the loss of
a broad range of QRP frequencies, as many can't seem to get exactly on .40.
 Can anyone enlighten me, off list is also okay if you don't want to clutter up
the list..  fred@...
> >Regards.. Fred
> >
> >
> >--
> >Fred Moore
> >Ham Radio:  WD8KNI
> >
> >Email: fred@...
> >Cell: 321-217-8699
> >
> >
>
>
> --
> Fred Moore
> Ham Radio:  WD8KNI
>
> Email: fred@...
> Cell: 321-217-8699
>

I have a Softrock that I bought second-hand from another user last year.  It
seems to hardly receive anything from 4 to 8 MHz, the bandpass filter #1 range. 
I'll get a few strong broadcast stations (unless they're images... I haven't
taken time to verify the frequencies on all of them) but hardly ever any hams or
utilities.  In fact, in some parts of the range, the signal display is virtually
flat.  All other bands work fine.  And, if I manually set the bandpass filter
selection from #1 to #2 (nominally 8-16 MHz), I get great, although sometimes
image-plagued, reception from 4-8 also.

I see comments here on the list about deafness being caused by failure to clean
the enamel from the coil wire before soldering it in, so I pulled up the
assembly instructions and schematics and tested for continuity through the
filter #1 inductors.  They're fine.  I don't know what else to try, because I
don't have a scope or a signal generator.

So, is the 4-8 MHz filter just a particularly bad filter (which I can hardly
believe would've been intentional, given the amount of activity on the 40m ham
band), or do I have something else going on?

I have seen your problem in the Softrock of a friend, it didn't select
the BPF for that band, either automatically or manually.  The problem
was a bad optoisolator, it originally was ok but it became bad later, I
don't know why. So your problem is either the filter itself, but you say
that you tested the coils for continuity, or the optoisolator (very rare
that this kind of failure repeats) or one of the switches .  Without a
scope you can check the output of the optos with a voltmeter while
exercising the filters in manual.  If ok then you can probe the
corresponding pins in the switches.  If the line that connects the opto
to the switch chips is always low maybe it is connected to ground by a
solder bridge, check with an ohmmeter with the power off.  You can also
monitor the DC levels of the working filters, both on and off, this can
give us a clue.

73 de Ignacio, EB4APL


On 24/02/2013 1:11, jmshaffer_pa wrote:

> I have a Softrock that I bought second-hand from another user last year.
> It seems to hardly receive anything from 4 to 8 MHz, the bandpass filter
> #1 range. I'll get a few strong broadcast stations (unless they're
> images... I haven't taken time to verify the frequencies on all of them)
> but hardly ever any hams or utilities. In fact, in some parts of the
> range, the signal display is virtually flat. All other bands work fine.
> And, if I manually set the bandpass filter selection from #1 to #2
> (nominally 8-16 MHz), I get great, although sometimes image-plagued,
> reception from 4-8 also.
>
> I see comments here on the list about deafness being caused by failure
> to clean the enamel from the coil wire before soldering it in, so I
> pulled up the assembly instructions and schematics and tested for
> continuity through the filter #1 inductors. They're fine. I don't know
> what else to try, because I don't have a scope or a signal generator.
>
> So, is the 4-8 MHz filter just a particularly bad filter (which I can
> hardly believe would've been intentional, given the amount of activity
> on the 40m ham band), or do I have something else going on?
>
>

In the testing section at the end of this stage of the build the manual says:

"Activate PTT. (As an alternative to using the SDR Software to activate PTT, you
can use a cliplead to ground the top left- hand lead of U4, activating PTT.)"

If I choose to use the 2nd method of activating PTT through U4 can someone
clarify which pin this refers to. I assume top left means PIN 4 but uncertain.

TNX for clarification. I'm anxious to finish the build FINALLY in the next day
or so.

Rick
W2JAZ

I finished my Ensemble RxTX and it works GREAT!

I made some CW and PSK31 contacts using Rocky.
I made an SSB contact using HDSDR
I made an RTTY contact using HDSDR and FLDigi with the CAT control working -- on
40m! It's a bit more complex installing virtual audio and virtual COMM ports to
do this but it sure works!

I am amazed at this thing!

I'm getting about 1 Watt out of the transmitter on 30/20/17 which it was built
for AND I'm getting about 1 Watt out on 40m. I don't know if I should be using
it on 40m but I thought I would try it to see what happens.

I haven't had this much fun building a radio since I built my Heathkit HW-100
transceiver back in the 70s.

Thanks to Tony and Robby for their work!!

Mike N9MS

Working on 40 should be fine but you will probably want a filter for the harmonic that you are probably transmitting on 20.

Dave
KB2YWT

On Feb 23, 2013, at 10:24 PM, richard.lawn@... wrote:

> In the testing section at the end of this stage of the build the manual says:
>
> "Activate PTT. (As an alternative to using the SDR Software to activate PTT,
you can use a cliplead to ground the top left- hand lead of U4, activating
PTT.)"
>
> If I choose to use the 2nd method of activating PTT through U4 can someone
clarify which pin this refers to. I assume top left means PIN 4 but uncertain.

Of the two pins on the non-USB side of the board, one is ground, and the other
is pin 4. So, easiest way is to short those pins with a screwdriver, clip-lead,
etc.

That package is called a DIP. Wikipedia has some information on pin numbering:

http://en.wikipedia.org/wiki/Dual_in-line_package#Orientation_and_lead_numbering

----- Original Message -----
Subject: [softrock40] Ensemble RxTX working great!


>AND I'm getting about 1 Watt out on 40m. I don't know if I should be using it
on 40m but I thought I would try it to see what
>happens.
>

Mike,

Glad it's working.
People who know better than me have said never use a Softrock for TX on a band
outside those where it is designed to work.
The reason given is that you risk in-band spurii that cannot be filtered out.

73 Alan G4ZFQ

----- Original Message -----
Subject: [softrock40] TX Mixer Testing Question


> In the testing section at the end of this stage of the build the manual says:
> "Activate PTT. (As an alternative to using the SDR Software to activate PTT,
you can use a cliplead to ground the top left- hand
> lead of U4, activating PTT.)"
>
> If I choose to use the 2nd method of activating PTT through U4 can someone
clarify which pin this refers to. I assume top left
> means PIN 4 but uncertain.
>

Rick,

I'd say use CFGSR, it's safer.
U4 is shown in the LO page.

73 Alan G4ZFQ

I have been following the recent discussions on SoftRock dynamic range and
intermodulation with great interest. Here is my personal experience.
During the evenings I received a lot of intermodulation products on my RXTX
40/30/20 in the 20m band.
Several AM modulated carriers spaced at exactly 5kHz did not shift up or down
during tuning. My first impression was that the SI570 didn't change frequency.
But it obviously are intermodulation products from broadcast stations. I
uploaded a HDSDR screen capture to the PA1GVE album to show this behavior.
Tuning across the full range revealed that broadcast stations in the 49m band
(6MHz) were the cause of the IM products. Levels of up to S9+60dB were measured.
600mVpp was measured on RX ANT (Q11.d) and 400mV on the antenna input. The audio
output was less than 100mVpp.
Placing attenuators just before and just after the QSD mixer showed that the QSD
mixer was the source of the IM products.
Since the RXTX showed 25dB of noise floor rise on 40m when connecting to the
antenna and only 10dB-12dB on 20m, the obvious solution to eliminate the IM is
to change the filter response such that 6 and 7MHz are attenuated 18 to 20dB and
14MHz 5-8dB at maximum.
A transfer measurement from the antenna connector to the primary of the QSD
transformer T5 showed that in the original circuit 14MHz is 4dB weaker than
7MHz, contrary to what is needed.
This response is probably not as it was intended. Maybe because 2 filters were
placed in series without proper terminations. The first filter (L3, L2, C26,
C25, C24) is not terminated into 50 Ohm and the second filter (C27, L4, C39, T5)
is not fed from a 50 Ohm source. Inserting a 3dB pad between both filters
already removed the dip at 17MHz and the peak at 18MHz.
Some tweaking resulted in the following changes: C27 1nF (was 330p), 8dB pad
(120, 56, 120 Ohm) between Q10/Q11 and L4, 100pF in series with L4, C39 330pF
(was 470p), C25 390pF (was 470pF). The change of C25 also reduces the insertion
loss on 20m to below 0.5dB.
Compared to the original circuit 6MHz is reduced by 18dB, 7MHz is reduced by
15.5dB, 10MHz is reduced by 11dB and 14MHz is reduced by 5dB only.
The measured receive filter responses can be seen in the PA1GVE album.

The result is that all IM products are gone, even if the RXTX is set to 14MHz
and the antenna tuner is set to 6MHz. All three bands still show a 5-10dB noise
floor increase when the antenna is connected and properly tuned.
Similar considerations might be valid for the other (bands) versions of the
RXTX. These could also benefit from the receiver attenuator and the decoupling
of the two filters.
My RX II Ensemble has much less IM problems. On 14MHz the preselector bandwidth
is from 8MHz to 16MHz. So 6MHz is sufficiently attenuated (18dB). Both
preselector filters below 8MHz have attenuators (close to 15dB).
If the RX II Ensemble is set 14MHz and the antenna tuner is set to 6MHz then
sometimes broadcast stations can be heard on the spectrum center line (LO
freq=tune freq), independent from RX II LO frequency. But it is hardly visible
in the spectrum.

73, Gerhard PA1GVE

Jose,

i do not understand you response. Do you think my message is too long?

I simply shared my experience with intermodulation. Maybe others can benefit.

73 Gerhard PA1GVE

--- In softrock40@yahoogroups.com, Jose Bonanca <jabct1aos@...> wrote:
>
> Did you think you were writing a book.?
> 73
>
>
>
> On 24 February 2013 14:08, gerhard972 <gerhard.vaneerden@...>wrote:
>
> > **
> >
> >
> > I have been following the recent discussions on SoftRock dynamic range and
> > intermodulation with great interest. Here is my personal experience.
> > During the evenings I received a lot of intermodulation products on my
> > RXTX 40/30/20 in the 20m band.
> > Several AM modulated carriers spaced at exactly 5kHz did not shift up or
> > down during tuning. My first impression was that the SI570 didn't change
> > frequency. But it obviously are intermodulation products from broadcast
> > stations. I uploaded a HDSDR screen capture to the PA1GVE album to show
> > this behavior.
> > Tuning across the full range revealed that broadcast stations in the 49m
> > band (6MHz) were the cause of the IM products. Levels of up to S9+60dB were
> > measured. 600mVpp was measured on RX ANT (Q11.d) and 400mV on the antenna
> > input. The audio output was less than 100mVpp.
> > Placing attenuators just before and just after the QSD mixer showed that
> > the QSD mixer was the source of the IM products.
> > Since the RXTX showed 25dB of noise floor rise on 40m when connecting to
> > the antenna and only 10dB-12dB on 20m, the obvious solution to eliminate
> > the IM is to change the filter response such that 6 and 7MHz are attenuated
> > 18 to 20dB and 14MHz 5-8dB at maximum.
> > A transfer measurement from the antenna connector to the primary of the
> > QSD transformer T5 showed that in the original circuit 14MHz is 4dB weaker
> > than 7MHz, contrary to what is needed.
> > This response is probably not as it was intended. Maybe because 2 filters
> > were placed in series without proper terminations. The first filter (L3,
> > L2, C26, C25, C24) is not terminated into 50 Ohm and the second filter
> > (C27, L4, C39, T5) is not fed from a 50 Ohm source. Inserting a 3dB pad
> > between both filters already removed the dip at 17MHz and the peak at 18MHz.
> > Some tweaking resulted in the following changes: C27 1nF (was 330p), 8dB
> > pad (120, 56, 120 Ohm) between Q10/Q11 and L4, 100pF in series with L4, C39
> > 330pF (was 470p), C25 390pF (was 470pF). The change of C25 also reduces the
> > insertion loss on 20m to below 0.5dB.
> > Compared to the original circuit 6MHz is reduced by 18dB, 7MHz is reduced
> > by 15.5dB, 10MHz is reduced by 11dB and 14MHz is reduced by 5dB only.
> > The measured receive filter responses can be seen in the PA1GVE album.
> >
> > The result is that all IM products are gone, even if the RXTX is set to
> > 14MHz and the antenna tuner is set to 6MHz. All three bands still show a
> > 5-10dB noise floor increase when the antenna is connected and properly
> > tuned.
> > Similar considerations might be valid for the other (bands) versions of
> > the RXTX. These could also benefit from the receiver attenuator and the
> > decoupling of the two filters.
> > My RX II Ensemble has much less IM problems. On 14MHz the preselector
> > bandwidth is from 8MHz to 16MHz. So 6MHz is sufficiently attenuated (18dB).
> > Both preselector filters below 8MHz have attenuators (close to 15dB).
> > If the RX II Ensemble is set 14MHz and the antenna tuner is set to 6MHz
> > then sometimes broadcast stations can be heard on the spectrum center line
> > (LO freq=tune freq), independent from RX II LO frequency. But it is hardly
> > visible in the spectrum.
> >
> > 73, Gerhard PA1GVE
> >
> >
> >
>
>
>
> --
> Jose (Ct1aos)
>

Jose

If you don't appreciate detailed information then I suggest you don't bother to
read it. Those of us that do would like to encourage all the detail a
contributor is willing to provide  us.

Warren Allgyer -W8TOD


--- In softrock40@yahoogroups.com, Jose Bonanca <jabct1aos@...> wrote:
>
> Did you think you were writing a book.?
> 73
>
>
>
> On 24 February 2013 14:08, gerhard972 <gerhard.vaneerden@...>wrote:
>
> > **
> >
> >
> > I have been following the recent discussions on SoftRock dynamic range and
> > intermodulation with great interest. Here is my personal experience.
>
>

Is it feasible to build the Ensemble RXTX for 60m/40m/30m?

Nick G3VNC

Tnx. Ill use the CFGSR. I found the previous install section covering U4 but was
unclear which pin they were referring to based on board orientation. I assumed
pin 4.
Rick

--- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
>
>
> ----- Original Message -----
> Subject: [softrock40] TX Mixer Testing Question
>
>
> > In the testing section at the end of this stage of the build the manual
says:
> > "Activate PTT. (As an alternative to using the SDR Software to activate PTT,
you can use a cliplead to ground the top left- hand
> > lead of U4, activating PTT.)"
> >
> > If I choose to use the 2nd method of activating PTT through U4 can someone
clarify which pin this refers to. I assume top left
> > means PIN 4 but uncertain.
> >
>
> Rick,
>
> I'd say use CFGSR, it's safer.
> U4 is shown in the LO page.
>
> 73 Alan G4ZFQ
>