Date   

Upcoming Event: Wednesday Evening 40 and 80 meter Nets - Wed, 04/22/2020 20:00-21:00 #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: Wednesday Evening 40 and 80 meter Nets

When: Wednesday, 22 April 2020, 20:00 to 21:00, (GMT-05:00) America/Chicago

Where:40 and 80 Meters

View Event

Organizer: jomatlock@...

Description: The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP Operator to be determined.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


Re: Ozark Patrol Tuning adjustment question

Jerome Wysocki
 

I heard the same story about radiation from the regenerative Paraset receivers, and how they could be tracked down with direction finding radio receivers. So I fired up one of my experimental regenerative radios, but only used about 32 volts for the detector B+. It regenerated fine so I took a small portable hand held short wave radio with me for a walk around the neighborhood. With the set in my house still oscillating, I could pick up its radiated signal for at least several hundred feet away from my house. Imagine the range I could have gotten if I increased to detector B+ up to around 250 volts or so, typically to what a regenerative Paraset radio would be operating with. No wonder they were careful to minimize listening time!


Re: Ozark Patrol Tuning adjustment question

Curt
 

So the British actually charged people a fee to LISTEN to a radio??!!  Wonder how their DF vans would have dealt with a crystal set.  Maybe if caught with a 1N34A or Oatmeal box wound with wire in the house the bobbies would put the cuffs on :-o

Curt KB5JO


Re: Ozark Patrol Tuning adjustment question

Tom Denton
 

When I asked this question of Russ Ramirez, this was his reply: 


On Sun, Mar 24, 2019, 5:11 PM Russ Ramirez <russ.ramirez@...> wrote:
Typically to get a dial on a receiver, signal generator, etc. you have an adjustable coil for the low-end of the band in question and a variable cap for the high end. In this case, the inductance is fixed and yes, the 560 pf capacitor can probably be increased a little to bring things in line. A 680 pf cap may not be excessive, but if it is, then another cap in parallel will be additive. If you happen to have a small trimmer cap to solder in parallel, that would be a good way to dial things in.

 


Re: Ozark Patrol Tuning adjustment question

Frank Perkins
 

No Gwen,
Those British vans are searching for tea &  crumpet shops!    :-)
Frank N6CES

On Wed, Apr 22, 2020, 9:32 AM Gwen Patton <ardrhi@...> wrote:
Perhaps our British members might be able to verify if this is how the BBC's roving radio detection vans would locate people who hadn't paid their radio license fees? I've seen pictures of these vans, with DF loops on them, to sniff out scofflaws, and I wonder if that's what they were designed to detect.

73,
Gwen, NG3P

On Wed, Apr 22, 2020 at 10:43 AM Curt via groups.io <rhulett1=consolidated.net@groups.io> wrote:
"I believe with the 560 pF capacitor switched in the circuit, to parallel it to c1 (the 365 pF variable tuning capacitor) you are on the higher frequency band, and when c11 is not in parallel with c1, you are tuning the lower frequency band. (I hope my logic isn't reversed here.)"

To clarify, with the 560 pF switched into the circuit, the resonant frequency of the circuit with the 1.6 uH tank, will be about 3.7 MHz.  With it switched out, the frequency will be about 7 MHz.  I listen to the oscillator in another receiver to find where the Ozark is tuned.

I have read that the Paraset regenerative receivers used by resistance in WW2 put out strong signals from their oscillators that Gestapo used to locate the clandestine radios.  The operators had to limit their time listening to decrease possibility of being detected ( and executed ).

Curt KB5JO



--

-+-+-+-+-
Jenny Everywhere's Infinite: Quark Time
http://quarktime.net


Re: Ozark Patrol Tuning adjustment question

w9ran
 

On 4/22/2020 11:32 AM, Gwen Patton wrote:
Perhaps our British members might be able to verify if this is how the BBC's roving radio detection vans would locate people who hadn't paid their radio license fees? I've seen pictures of these vans, with DF loops on them, to sniff out scofflaws, and I wonder if that's what they were designed to detect.
Not since 1971: https://www.sixtiescity.net/Television/Licences.htm

I suspect by then there were few if any regens still in use,  but while radio licenses were required those vans did try to DF the weak radiation from local oscillators in superhet receivers in an attempt to find unlicensed receivers.   Had to be unrewarding work ;-)

73, Bob W9RAN


Re: Ozark Patrol Tuning adjustment question

Gwen Patton
 

Perhaps our British members might be able to verify if this is how the BBC's roving radio detection vans would locate people who hadn't paid their radio license fees? I've seen pictures of these vans, with DF loops on them, to sniff out scofflaws, and I wonder if that's what they were designed to detect.

73,
Gwen, NG3P

On Wed, Apr 22, 2020 at 10:43 AM Curt via groups.io <rhulett1=consolidated.net@groups.io> wrote:
"I believe with the 560 pF capacitor switched in the circuit, to parallel it to c1 (the 365 pF variable tuning capacitor) you are on the higher frequency band, and when c11 is not in parallel with c1, you are tuning the lower frequency band. (I hope my logic isn't reversed here.)"

To clarify, with the 560 pF switched into the circuit, the resonant frequency of the circuit with the 1.6 uH tank, will be about 3.7 MHz.  With it switched out, the frequency will be about 7 MHz.  I listen to the oscillator in another receiver to find where the Ozark is tuned.

I have read that the Paraset regenerative receivers used by resistance in WW2 put out strong signals from their oscillators that Gestapo used to locate the clandestine radios.  The operators had to limit their time listening to decrease possibility of being detected ( and executed ).

Curt KB5JO



--

-+-+-+-+-
Jenny Everywhere's Infinite: Quark Time
http://quarktime.net


Re: Ozark Patrol Tuning adjustment question

Curt
 

"I believe with the 560 pF capacitor switched in the circuit, to parallel it to c1 (the 365 pF variable tuning capacitor) you are on the higher frequency band, and when c11 is not in parallel with c1, you are tuning the lower frequency band. (I hope my logic isn't reversed here.)"

To clarify, with the 560 pF switched into the circuit, the resonant frequency of the circuit with the 1.6 uH tank, will be about 3.7 MHz.  With it switched out, the frequency will be about 7 MHz.  I listen to the oscillator in another receiver to find where the Ozark is tuned.

I have read that the Paraset regenerative receivers used by resistance in WW2 put out strong signals from their oscillators that Gestapo used to locate the clandestine radios.  The operators had to limit their time listening to decrease possibility of being detected ( and executed ).

Curt KB5JO


Upcoming Event: Wednesday Evening 40 and 80 meter Nets - Wed, 04/22/2020 20:00-21:00 #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: Wednesday Evening 40 and 80 meter Nets

When: Wednesday, 22 April 2020, 20:00 to 21:00, (GMT-05:00) America/Chicago

Where:40 and 80 Meters

View Event

Organizer: jomatlock@...

Description: The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP Operator to be determined.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


Re: Ozark Patrol Tuning adjustment question

Timothy East
 

I was very happy to see the mods for the Murania kit to really improve its performance.
Is there a list of mods that I can use to improve my OZark Patrol?

Tim
K0EMP

On Apr 21, 2020, at 19:00, Jerome Wysocki <jeromewysocki48@...> wrote:

Thanks, Curt. Your audio files sound just like my receiver does on 80 and 75 meters, but only after the addition of the 10 ohm resistor to the one turn feedback coil going through the center of the torroid coil, as I described it. Mine does not like long antennas, so I use a 30 foot longwire. Furthermore, I substituted a small adjustable trimmer capacitor to replace the gimmick capacitor in the original design. This allows me to better control the input from possible overload by reducing the coupling with the antenna. Adjusting that trimmer helped me do precisely that.

I tried substituting a 2N2222 for the original detector transistor, but found nothing really significantly different in receiver performance with either one. All resistors were within spec when I tested them, prior to installation. Maybe some critical capacitors surrounding the detector transistor are marginal, relative to their specs, and are just off enough to cause the problem I am having. (I carefully observed that no mistakes were made in part identifications, prior to soldering them into place.) No solder bridges or cold joints were observed either, as far as I can see. Voltages appear normal.

Thanks again, Curt. I'm sure I'm missing something simple, and I'll probably kick myself when I find it 🙂. Meanwhile, it works really well on cw and ssb on 80 and 75 meters, and is good enough for a QRP cw receiver on that band.

... Jerry Wysocki, KC9JXE



Re: Ozark Patrol Tuning adjustment question

Jerome Wysocki
 

Thanks, Curt. Your audio files sound just like my receiver does on 80 and 75 meters, but only after the addition of the 10 ohm resistor to the one turn feedback coil going through the center of the torroid coil, as I described it. Mine does not like long antennas, so I use a 30 foot longwire. Furthermore, I substituted a small adjustable trimmer capacitor to replace the gimmick capacitor in the original design. This allows me to better control the input from possible overload by reducing the coupling with the antenna. Adjusting that trimmer helped me do precisely that.

I tried substituting a 2N2222 for the original detector transistor, but found nothing really significantly different in receiver performance with either one. All resistors were within spec when I tested them, prior to installation. Maybe some critical capacitors surrounding the detector transistor are marginal, relative to their specs, and are just off enough to cause the problem I am having. (I carefully observed that no mistakes were made in part identifications, prior to soldering them into place.) No solder bridges or cold joints were observed either, as far as I can see. Voltages appear normal.

Thanks again, Curt. I'm sure I'm missing something simple, and I'll probably kick myself when I find it 🙂. Meanwhile, it works really well on cw and ssb on 80 and 75 meters, and is good enough for a QRP cw receiver on that band.

... Jerry Wysocki, KC9JXE


Re: Ozark Patrol Tuning adjustment question

Curt
 

Here is what it sounds like on 40M:


Re: Ozark Patrol Tuning adjustment question

Curt
 

My regeneration works well on both bands.  I listen to 80 & 75 in the evening, 40, 30, and 20 during the day.  I added a little tiny LM386 audio amplifier so now can listen to everything without headphones. 

My only issue, which isn't a large one is that my tuning cant match up the the index marks on the dial. 

Curt KB5JO


Re: N75 Saturday Morning Gathering.

Charles W. Powell
 

I’m missing out on the fun here!

73,

Charles - 5H3DX

On Apr 18, 2020, at 3:14 PM, Johnny Matlock <jomatlock@...> wrote:

Gm Group:
We’re going to have a informal round table get together on 3.730 AM plus or minus qrm this morning at 9:00 am CDST.
Hope to see you there!
72
Johnny AC0BQ 

--
Check out the 4SQRP website at 4sqrp.com


Upcoming Event: Wednesday Evening 40 and 80 meter Nets - Wed, 04/22/2020 20:00-21:00 #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: Wednesday Evening 40 and 80 meter Nets

When: Wednesday, 22 April 2020, 20:00 to 21:00, (GMT-05:00) America/Chicago

Where:40 and 80 Meters

View Event

Organizer: jomatlock@...

Description: The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP Operator to be determined.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


Re: Ozark Patrol Tuning adjustment question

Jerome Wysocki
 

Hi Curt,

The most likely thing to do, I think, is to replace (change the value) of c11, a 560 pF capacitor, that is wired to the toggle switch, that is your band switch. I believe with the 560 pF capacitor switched in the circuit, to parallel it to c1 (the 365 pF variable tuning capacitor) you are on the higher frequency band, and when c11 is not in parallel with c1, you are tuning the lower frequency band. (I hope my logic isn't reversed here.)

I also found that increasing the battery voltage from 9 to 15 volts, the tuning ranges changed noticeably on both bands. That might be another option to experiment with. (15 volts also gives much higher audio to the speaker.)

How is your regeneration control doing? Mine was very unstable on both bands until I inserted a 10 ohm resistor in series with the one turn (feedback) loop that goes to the center of the torroid coil ring. (I've built a number of regenerative receivers before, so am familiar with good ones and unstable ones.) I connected the resistor to the one turn loop, on the side that was outside the center of the torroid coil. That vastly improved the stability of the regeneration control. Encouraged by this, I will fine tune the resistor value to see if I can get even smoother regeneration. (Greater that 10 ohms, and I lose all regeneration, but I might get better stability with, say 8 ohms. I will have to try this.)

How does the performance on the two bands of your receiver compare? Mine is now very stable and useable for cw and ssb on 80 meters, but no luck yet on the top band, for 40 meters.

Hope this helps you out.

... Jerry Wysocki, KC9JXE


qrparci reflector at groups.io

Jim Stafford W4QO
 

Still plenty of openings for the qrparci reflector.
450 members so far.  Lots of contest chit chat.
You may/should advertise your QRP contests
and/or activities on this club reflector.
 
For example, check out the posts to the recent SPRING
QSO PARTY event:  qrpcontest.org with over 60 entries.
 
Click on SPRING QSO PARTY…  
It all happened due to huge publicity on the qrparci
reflector: qrparci.groups.io  Take a look; the posts
or open to read and easily searchable.
 
You do not have to be a club member to join this reflector but
if you are a member of qrparci, this is your
club’s reflector.  Ask questions, get latest news, when
QQ ships, etc.
 
If your email address does not include your callsign…
the also send your callsign to cw at w4qo.com
 
qrparci.groups.io    Then hit the SUBSCRIBE button.
 
Have you checked out the RBN skimmer for
members of various CW clubs:
http://rbn.telegraphy.de/  Good way to spot
SKCC, CW OPS, QRPARCI, etc.  To see your
callsign, just call CQ or send TEST followed by
your callsign.  This assumes you belong to one
of the clubs listed.
 
NOTE: this is not trying to take traffic away
from QRP-L or any other reflector.  With so
many sitting inside these days, plenty of time to
read lots of ham radio news…. 
 
And check out the FL QSO PARTY this weekend:
QRP category!  Lots of stations on the air from FLA...
 
 
Take care.
 
jim/w4qo
qrparci #6515
  •  


Ozark Patrol Tuning adjustment question

Curt
 

Can anyone advise about adjusting the Ozark Patrol tuning range?  On the top band, mine covers 4.6-16.2 MHz, a range of 11.6.  The marked dial is 5-12 or a range of 7.
On the bottom band it covers 3.3 - 4.5 range of 1.2, marked range 3-5 range of 2  So the range is small on the lower band but wide on the upper band.

The radio functions fine as it stands, but would like to get it set closer to the dial.  I am wondering if adjusting the pad/trim trimmers on the variable capacitor would provide some improvement? 

Suggestions?

Curt KB5JO


Re: Solder Paste / Flux ... where to buy

Johnny AC0BQ
 

Thanks for the info Charles.
I didn’t know we had a new Radio Shack In town.
73
Johnny AC0BQ 

On Sun, Apr 19, 2020 at 7:43 AM Charles Wells <odu1993@...> wrote:
I'm not sure about the quality.  Their stock is a real mix of old and new with some 3rd party packaged components.  Since I tend to not buy one's and twos of parts (usually cheaper by the dozen) I don't go in often.

On Sun, Apr 19, 2020, 07:09 Nate Bargmann <n0nb@...> wrote:
* On 2020 18 Apr 18:54 -0500, Charles Wells wrote:
> We've a Radio Shack in our smaller town of Emporia, KS.  Opened fairly
> recently.  The proprietor told me that all of the RS now operating or
> opening are independent franchise stores.  He indicated that RS corporate
> would continue to supply inventory for a long time.

Has the quality of the parts been improved?  I recall connectors that
had insulation that looked like Teflon but when soldered would melt like
cheap PVC.

72, Nate

--

"The optimist proclaims that we live in the best of all
possible worlds.  The pessimist fears this is true."

Web: https://www.n0nb.us
Projects: https://github.com/N0NB
GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819




--
Check out the 4SQRP website at 4sqrp.com


Re: Solder Paste / Flux ... where to buy

Charles Wells
 

I'm not sure about the quality.  Their stock is a real mix of old and new with some 3rd party packaged components.  Since I tend to not buy one's and twos of parts (usually cheaper by the dozen) I don't go in often.


On Sun, Apr 19, 2020, 07:09 Nate Bargmann <n0nb@...> wrote:
* On 2020 18 Apr 18:54 -0500, Charles Wells wrote:
> We've a Radio Shack in our smaller town of Emporia, KS.  Opened fairly
> recently.  The proprietor told me that all of the RS now operating or
> opening are independent franchise stores.  He indicated that RS corporate
> would continue to supply inventory for a long time.

Has the quality of the parts been improved?  I recall connectors that
had insulation that looked like Teflon but when soldered would melt like
cheap PVC.

72, Nate

--

"The optimist proclaims that we live in the best of all
possible worlds.  The pessimist fears this is true."

Web: https://www.n0nb.us
Projects: https://github.com/N0NB
GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819