Hi all , after a huge silence ,I am here again with a nice
  VFO  called BLUBERRY .
  It is a small evaluation board for a Cypress chip.

  It ca be programmed easily via USB with the given CyberClock
  program.

   The frequency range that could be obtained is from 80 khz
    to 160 MHZ with a good coverage.

   I will create in files a directory called CYBER_CLOCK.
   with all the relative infos.

   I am looking for chips FST3125 to build minimal QRSSRX
   for all HF bands.
   I would like to use the G4OEP nice schematic.

   I know that the jitter will be more than the tiny Si570
   but I am interrested to give to this CYPRESS chip a try.


                                     73 all de Paolo IZ1KXQ

----- Original Message -----

From: Timothy Stabler

To: qrsstxrx@yahoogroups.com

Sent: Thursday, July 31, 2008 3:51 PM

Subject: [qrsstxrx] Clubhouse

I am sorry I did not send anything before, but I am the clubhouse columnist for QRP Quarterly. If there are club members in this group, how about swending me what your club is doing (along with pictures and captions please).

My next column is due September 1, but I am trying to get it done as soon as possible due to my wife and I have started building a house and there is always something else,we have to decide on.

Thanks much.

Tim
WB9NLZ

No virus found in this incoming message.
Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.5.9/1583 - Release Date: 7/31/2008 6:17 AM

I am sorry I did not send anything before, but I am the clubhouse columnist for
QRP Quarterly.  If there are club members in this group, how about swending me
what your club is doing (along with pictures and captions please).

My next column is due September 1, but I am trying to get it done as soon as
possible due to my wife and I have started building a house and there is always
something else,we have to decide on.

Thanks much.

Tim
WB9NLZ

Hi,

I am new to this group, I joined recently after searching the web for
stuff and finding the website of G4OEP ( Dr. Andrew Smith ).

I am a licensed amateur since a couple of years, I am quite into
building HW and experimenting things I find this whole idea of QRSS
very intriguing and fascinating.

To make it short "I'd love to try it too", I really want to see how
this "very low power long distance transmission" works it sounds very
interesting.

I studied a little bit around there and there, so basically is some
slow FSK modulation ( or just CW ) done using a very stable frequency
transmitter usually made with some heated quartz.

Sounds nice, so what kind of suggestions/hints would you give to a
neophite that would like to experiment with this ?

Currently my rig is a G5RV aerial and I have a FT-840 receiver plus a
Softrock radio I recently built, it seems anyway you need some
dedicated receiver if you wish to receive this kind of stuff ?

I suppose I could/should start doing a bit of practice in receiving
this stuff before to try to build a transmitter and start to try
something myself, do you think it's a good idea ?

How does it work that thing ? Do you have a transmitter that
constantly transmits something in some frequency and people tries to
pick it up and/or you transmit "only for a while at certain times"
and people try to get you up ?

Any help appreciated, I think this idea is very interesting.

Thanks in advance,

Ivan Z.

--- In qrsstxrx@yahoogroups.com, "Stan" <ak0b@...> wrote:
>
> Looking for a site with activity on MEPT circuits
>
> interested in G3zjo unit he shows in the You Tube videos
>
> Stan ak0b
>

It all happens on the QRSS Knights mail list:
http://mail.cnts.be/mailman/listinfo/knightsqrss_cnts.be

regards
   Clayton
   VK1TKA

Looking for a site with activity on MEPT circuits

interested in G3zjo unit he shows in the You Tube videos

Stan ak0b

---

To: qrsstxrx@yahoogroups.com
From: martin.peters@...
Date: Tue, 3 Jun 2008 22:45:25 +0000
Subject: [qrsstxrx] 7MHz xtal anyone?

hello. Does anyone konw where i can et hold of a 7MHz crystal? I'd
like to build the QRPp QRSS TX featured in the latest SPRAT magazine.
Thanks for your help.

Martin - G4EFE

I have some in HC49U.

If you like contact me pm with quantity and your address for postal
calculation.


regards -
Henry


g4efe schrieb:
> hello. Does anyone konw where i can et hold of a 7MHz crystal? I'd
> like to build the QRPp QRSS TX featured in the latest SPRAT magazine.
> Thanks for your help.
>
> Martin - G4EFE
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

--
www.ehydra.dyndns.info

hello. Does anyone konw where i can et hold of a 7MHz crystal? I'd
like to build the QRPp QRSS TX featured in the latest SPRAT magazine.
Thanks for your help.

Martin - G4EFE

Hallo guys,

this message is in order to inform you that at this time we are
publishing
an "Home Made Newsletter" Called HMN (Home Made News), and we have a
newsgroup too, at address
http://it.groups.yahoo.com/group/HomeMadeNews/ .

The aim is to inform and show news about homebrew, websites,
products, and
so on about this theme.
The sheet is mainly in Italian Language, but there are also few
parts in
English as technique materials in the world are in English so we are
trying
to make a semi-double-language newsletter for Italian Hams too!

If you like to receive, freely of course, the newsletter, please let
me
know, and I'll send next issues by email. If you like to see past
issue, we
have a server where we'll put all we want to share with other
homebrewers,
and NL too, at address http://www.eco-lavoro.com/hmn/ that is
splitted in
several sections (in the Bulletin there are the two past issue of
NL).

Hope this is useful for you, have my best 73


Alex - I0SKK

Alessandro Santucci

I QRP C #305

INORC # 536

ARI Telegraphy Club
Honorary Member #62

email: i0skk@...

Web: www.eco-lavoro.com/i0skk

I was reading all your message and I am starting now to develop my own
RX .......in the next future more about that... 73 de IK4GBU-Valerio

Hi Chris , for local problems the file uploading  failed.
Now the OCTOBER version of my 30mt_QRSSRX is available on "files".
I hope it will be useful.

                                           73 de Paolo I1DFS


--- In qrsstxrx@yahoogroups.com, "Christian \(DL6JAN\)" <dl6jan@...>
wrote:
>
> Hi Paolo,
>
> sri, cannot find the schematics in "Yahoo files".
>
> Chris, DL6JAN
>
>
> --------------------------------------------------------------------
------------
>
>
>
>   ----- Original Message -----
>   From: Paolo Saia
>   To: qrsstxrx@yahoogroups.com
>   Sent: Tuesday, October 10, 2006 3:00 PM
>   Subject: [qrsstxrx] I1DFS Files updating
>
>
>   Hi all
>   I have just loaded on files my actual RX schematic .
>   I added the tiny chip MAX2620 as XTAIL Oscillator .
>
>   73 de Paolo IZ1KXQ / I1DFS
>

--- In qrsstxrx@yahoogroups.com, "Christian \(DL6JAN\)" <dl6jan@...>
wrote:
>
> Hi Paolo,
>
> sri, cannot find the schematics in "Yahoo files".
>
> Chris, DL6JAN
>
>
Hi Chris,

Just had a look and it's on there now.

Les, G3VYZ
>
--------------------------------------------------------------------------------
>
>
>
>   ----- Original Message -----
>   From: Paolo Saia
>   To: qrsstxrx@yahoogroups.com
>   Sent: Tuesday, October 10, 2006 3:00 PM
>   Subject: [qrsstxrx] I1DFS Files updating
>
>
>   Hi all
>   I have just loaded on files my actual RX schematic .
>   I added the tiny chip MAX2620 as XTAIL Oscillator .
>
>   73 de Paolo IZ1KXQ / I1DFS
>

----- Original Message -----

From: Paolo Saia

To: qrsstxrx@yahoogroups.com

Sent: Tuesday, October 10, 2006 3:00 PM

Subject: [qrsstxrx] I1DFS Files updating

Hi all
I have just loaded on files my actual RX schematic .
I added the tiny chip MAX2620 as XTAIL Oscillator .

73 de Paolo IZ1KXQ / I1DFS

Hi all
I have just loaded on files my actual RX schematic .
I added the tiny chip MAX2620 as  XTAIL Oscillator .


73 de Paolo IZ1KXQ / I1DFS

Hi - I am still ruminating over my rx design (look here -
http://g4oep.atspace.com/qrss/qrss.htm ) and am beginning to realise
that the inductors in the front end are a weak point re IP3.  In the
absence of equipment to measure this, I have been thinking about the
1dB compression point, which is supposed to be 10 to 12dB below the
ip3.  Compression is readily measurable, so I will eventually get
round to measuring it.

Meanwhile, can anyone point me in the direction of establishing a
theoretical derivation of the relationship between these quantities ?

The thing about the inductors is this - If we estimate 44dBm for the
IP3 of this type of mixer in its unmodified form, then take off 12dB
you are left with 1W for the 1dB compression point.  This is 10Vpk
into 50 ohms, and I just don't think the cores I have used are up to
this with just 1 turn on the primary - they are almost certain to
saturate, or at least be close enough to it to produce some
compression.  There is also the question of how the crystals would
perform at 3 times this level (connected to the secondary of the input
transformer).

Using tuned matching transformers in the filter is attractive because
they enable the filter to be tuned accurately on to the required
passband frequency, and supress spurious responses to an acceptable
level.  But I feel that this part of the design needs a re-think if
IP3 is to be optimised.  This raises the general question of front-end
filter design - even if a conventional LC filter is used, the cores
are definitely in the firing line and need care.

Andy G4OEP

--- In qrsstxrx@yahoogroups.com, "tigger" <aj-smith@...> wrote:
[snip]
> I am curious to know where our new members have been recruited from -
> has this group been referenced on some other group which we should
> know about ?
[snip]
> 73,  Andy G4OEP
>

I think we're all coming in from the EMRFD group since, Stan, ak0b,
posted in message http://groups.yahoo.com/group/emrfd/message/157
yesterday...


..."If you have not noticed over the past couple of years the mixer
technology available and low cost components to implement H-mode has
just exploded.

There is one group on Yahoo who has been adding just about
everything in print on the subject to their files section (qrsstxrx
· qrss tx/rx)..."

73,

Dan
w0uhf

Hi - There has been a wave of new members (5 in 24 hrs) joining the
group, and I would like to welcome them - I hope they will find (and
existing members continue to find) the group useful.

There has been little activity in this group recently, perhaps because
the question it has been asking has mainly been answered.

Meanwhile, I am very pleased with the qrss rx I have made, which
embodies the ideas discussed here, and I use it daily on the 10.140MHz
qrss subband.  It is described here -

http://g4oep.atspace.com/qrss/qrss.htm

I would like to develop a technique for measuring its IP3 point, but
at present I am holding off because I am not confident that I can make
a rf 2-tone source which has sufficiently low intermod components, or
measure them in anything I might make.

As far as I know, no-one has made a ssb qrss tx using one of the
filters we have talked about.

http://g4oep.atspace.com/crystal_filters/signal_frequency_crystal_filters.htm

Newcomers might find it useful to look in the 'Files' section of this
group - there is a huge collection of resource material there.

I am curious to know where our new members have been recruited from -
has this group been referenced on some other group which we should
know about ?

On the subject of groups, I hope that newcomers know about the 'Knights' -

Knightsqrss mailing list
Knightsqrss@...
http://mail.cnts.be/mailman/listinfo/knightsqrss_cnts.be
Knightsqrss clipboard http://www.on5ex.be

73,  Andy G4OEP

>
> Apparently there is a rule of thumb that says the third order
> intercept is  10 to 12 dB above the 1dB compression point:
>
> http://www.rfcafe.com/references/electrical/p1db.htm
> http://www.arrl.org/qex/2006/09/qx9letters.pdf
>
>
> Mike
> KL7R


looking at the philips data sheet for the sa602, this difference is
almost exactly 12dB

Andy

>
> Apparently there is a rule of thumb that says the third order
> intercept is  10 to 12 dB above the 1dB compression point:
>
> http://www.rfcafe.com/references/electrical/p1db.htm
> http://www.arrl.org/qex/2006/09/qx9letters.pdf
>
>
> Mike
> KL7R
>
This makes nonsense of the claim of 54dBm for 'our' mixer since 42dBm
is  15.8W, or 40v pk into 50 ohms.

This mixer cannot possibly be linear beyond an input voltage of 2.5v
pk, or 62.5mW  or 18dBm.  Add 12 to this and you get 30dBm as an
absolute maximum for estimated IP3.


The figures for a mixer with 3.5v bias are 1.5dB higher.


It is beginning to look as though an IP3 of 20dBm might be something
to hope for.

Andy G4OEP

> Apparently there is a rule of thumb that says the third order
> intercept is  10 to 12 dB above the 1dB compression point:
>
> http://www.rfcafe.com/references/electrical/p1db.htm
> http://www.arrl.org/qex/2006/09/qx9letters.pdf
>
>
> Mike
> KL7R
>
> PS
> Here are some docs I found on measuring third order intercept
>
>
http://www.downeastmicrowave.com/PDF/IP3.PDF#search=%22calculate%20third%20order\
%20intercept%22
> http://www.sm5bsz.com/dynrange/intermod.htm
>
http://www.odyseus.nildram.co.uk/Systems_And_Devices_Files/Linearity.pdf#search=\
%22calculate%20third%20order%20intercept%22
>
i Mike - thanks a lot for posting this material - it is extremely
informative, and answers my query about the sig level at which IP3
should be measured (it should be measured in a region wher e the 3rd
order output has a cubic relationship to input power).  It also
encourages me to feel that the problems I have identified are real
(necessity of output attenuator, hybrid, etc).

The 1dB compression point should be very easy to measure - I shall go
for that !

Andy G4OEP

Hi all
I have just loaded on files my actual RX schematic .

                                           73 de Paolo IZ1KXQ / I1DFS

> One thing I do think would be very informative is some kind of
> performance evaluation - preferably including IP3. I remember reading
> about a good way to do this but I don't remember where :-(
>
> 73 Hans G0UPL



Searching the net:

Apparently there is a rule of thumb that says the third order
intercept is  10 to 12 dB above the 1dB compression point:

http://www.rfcafe.com/references/electrical/p1db.htm
http://www.arrl.org/qex/2006/09/qx9letters.pdf


Mike
KL7R

PS
Here are some docs I found on measuring third order intercept

http://www.downeastmicrowave.com/PDF/IP3.PDF#search=%22calculate%20third%20order\
%20intercept%22
http://www.sm5bsz.com/dynrange/intermod.htm
http://www.odyseus.nildram.co.uk/Systems_And_Devices_Files/Linearity.pdf#search=\
%22calculate%20third%20order%20intercept%22

Hi Andy,

I read your new page, thanks for putting in the effort to write these
notes. I think I understand most of it but I probably still need to
re-read it a couple more times!

One thing I do think would be very informative is some kind of
performance evaluation - preferably including IP3. I remember reading
about a good way to do this but I don't remember where :-(

73 Hans G0UPL
http://www.hanssummers.com




On 9/9/06, tigger <aj-smith@...> wrote:
> Hi all.  I realise that the ideas behind my designs might not be
> obvious, so I have written some notes on my understanding of
> commutative mixers -
>
> http://g4oep.atspace.com/mixers/notes_on_the_basic_operation_of_.htm
>
> I hope that if this is read in conjuction with my previous posting in
> the files section (fs3125mixerorg.pdf), my ideas might be a little
> clearer.  Maybe I shall put these documents together at some stage.
>
> Best wishes to all
>
> Andy G4OEP
>

Hi all.  I realise that the ideas behind my designs might not be
obvious, so I have written some notes on my understanding of
commutative mixers -

http://g4oep.atspace.com/mixers/notes_on_the_basic_operation_of_.htm

I hope that if this is read in conjuction with my previous posting in
the files section (fs3125mixerorg.pdf), my ideas might be a little
clearer.  Maybe I shall put these documents together at some stage.

Best wishes to all

Andy G4OEP

--- In qrsstxrx@yahoogroups.com, "Hans Summers" <hans.g0upl@...> wrote:

> Nice work, and very interesting how you have arranged the transformers
> in the H-mode mixer.
>
> Interesting and worrying! I don't completely understand that
> transformer... it worries me because you are using the same core for
> your input transformer and your output transformer, is that Ok? Also
> is it Ok to be using that transformer at AF? I know that previously
> you were considering just summing the two complementary baseband
> outputs of the H-mode mixer using a differential amplifier. I wonder
> why you changed now to using the transformer? What would be the
> relative advantages and disadvantages of each?
>

Hi Hans - It is difficult to reply to this without going into a
complete explanation of how the h-mode mixer works.  Basically, in
this system there is no output transformer: I use the op-amp with its
100 Ohm input resistors instead.

If you compare my circuit with the classic design, you will see that I
have reversed the rf and if ports, and then replaced the output
transformer primaries (previously used for rf input) by 2 100ohm
resistors.  Finally I have combined the 2 transformers previously used
as if outputs into 1, and used it as an rf input.  The transformer is
an rf design, using a binocular core, and has no af function.   I
placed an explanation of this configuration (but using 2 input
transformers) on the files section about a month ago. It is worth
refering to that:- fstmixerorg.pdf

Really there is no alternative to some serious thinking about how this
mixer works.  It would resolve your doubts about the placing of 20.28
MHz filter capacitors as well (to remove the f*2 mixer output, and to
complete the 100ohm termination path to ground).  Notice I have placed
them after the 100 ohm filter-terminating resistors, as previously
discussed.

It might be useful for you to try to work out an af-output mixer
circuit for yourself; you would then see the logic of what I am doing.
  You might come up with an interesting alternative.

> It would be very interesting to measure. Do you have the right skills
> and equipment to measure IP3? I know I don't. That's another one for
> the G0UPL ToDo list.

I am still evaluating this design, and will give some thought to
trying to measure the IP3.  Paolo published a spectrum lab picture of
a mixer output spectrum, and that might be a way forward, but it is a
complex measurement even given the right equipment.  Basically you
have to measure how the 3rd order mixer output varies with input
amplitude, plot a graph, extrapolate the line, and see where the it
intersects the first order output line.  One should be direct
proportion, the other a cubic.  The data sheet for the SA602 gives an
example of the kind of plot that is needed.

Hello Andy

> Hi - I have been putting some of our ideas into practice, and have
> made my first attempt at a H-mode mixer rx.  The circuit is at -
>
> http://g4oep.atspace.com/qrss%20rx/qrss_ssb_receiver_with_h_mode_mi.htm

Nice work, and very interesting how you have arranged the transformers
in the H-mode mixer.

Interesting and worrying! I don't completely understand that
transformer... it worries me because you are using the same core for
your input transformer and your output transformer, is that Ok? Also
is it Ok to be using that transformer at AF? I know that previously
you were considering just summing the two complementary baseband
outputs of the H-mode mixer using a differential amplifier. I wonder
why you changed now to using the transformer? What would be the
relative advantages and disadvantages of each?

> The adaptation of the h-mode mixer for audio outoput is novel, as is
> the rf input configuration. I have reduced the number of transformers
> required to just one.  I am not aware that any concessions have been
> made which might compromise the intercept performance of the system.

It would be very interesting to measure. Do you have the right skills
and equipment to measure IP3? I know I don't. That's another one for
the G0UPL ToDo list :-(

73 Hans G0UPL
http://www.hanssummers.com

Hi - I have been putting some of our ideas into practice, and have
made my first attempt at a H-mode mixer rx.  The circuit is at -

http://g4oep.atspace.com/qrss%20rx/qrss_ssb_receiver_with_h_mode_mi.htm

This work is in progress, and I have not fully evaluated it yet, but
the system seems to be working as expected on the bench (no on-air
tests as yet).  The diagram is my first draught, and there might be
some errors.  Please let me know if there are any queries or obvious
errors.

The adaptation of the h-mode mixer for audio outoput is novel, as is
the rf input configuration. I have reduced the number of transformers
required to just one.  I am not aware that any concessions have been
made which might compromise the intercept performance of the system.

The conversion loss is very small.  The overall voltage gain from the
antenna to the output of the first opamp is 30, corresponding to an rf
loss of 4db, mostly attributable to the filter.  This seems very
promising.  The AD797 is a hyper low-noise device.

The lsb rejection is 40-45dB, and the af output abt 1.5kHz.

Andy G4OEP

Hi all,

finally after some days I was able to find again the original Harry's page,
the link is right: http://web.telia.com/~u85920178/

and in the Menu you have to look at "AF/amp circuits", the "3 W HF QRP" is
one I mean.
I prefer to point the original circuit as it's by Harry.
Anyway I tested it with several different BJT and had always good results.
Take care at the bias trimmer. If someone is interested I can supply some
pics of my last assembly, but I think Harry's page is more than enough. Hope
to be useful  73 to all group

Alex I0SKK


email: i0skk@...

Web: www.eco-lavoro.com/i0skk



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