Topics

Ozark Patrol Audio Transformer and Jack


Jerome Wysocki
 

Hi Dale,

I had the same problem you had with your Ozark Patrol. The regeneration on mine was very unstable, and almost as bad as you described with yours.

Here is what I did, so far. Besides the substitution of a 2N2222 for Q1 that I mentioned earlier, I added a small resistor in series with the one turn regeneration feedback loop that goes through the center of the torroid coil. The resistor I added was soldered to the lead of that one turn loop, that came OUT of the center of the torroid coil. I experimented with resistor values between 10 and 15 ohms. More than 15 ohms and the regeneration would quit entirely. I'm currently using 10 ohms with marginally acceptable results, but will further experiment with other values in search of better regeneration control stability.

I also replaced the antenna gimmick capacitor with a tiny 20 pF variable capacitor. That helped a little bit, too.

Keep us informed as to your success.

73s
... Jerry Wysocki, KC9JXE


Dale Hardin
 

I replaced Q1 with a 2n2222A.  I messaged Dave Cripes about the regeneration and he  suggested I needed to add a resistor on the emitter of Q1 to reduce the gain of the 2n2222A (that has more gain than the original transistor) as the regeneration was full on all the time (hope I said that right).  Did that, no joy--no regeneration point.  Dave also suggested I rewind L1.  I plan to do that.  While I am there, I will add the gimmick capacitor back to the circuit.  I think I am getting too much signal to the regeneration circuit.  At least I am learning more about how this receiver works.  Dale

On Tue, Aug 25, 2020 at 6:54 PM Curt via groups.io <rhulett1=consolidated.net@groups.io> wrote:
FWIW, mine has a most definite regeneration point.  So if yours isn't that isn't normal. 

Curt KB5JO



--
Dale Hardin
Elberta, AL 

--
Dale Hardin, KS4NS
Elberta, AL


Curt
 

FWIW, mine has a most definite regeneration point.  So if yours isn't that isn't normal. 

Curt KB5JO


Dale Hardin
 

Jerry, thanks for the hint.  I gave the 2n2222 a try and now get signals.  A big step closer to finishing.  Now, I am going to rebuild the regeneration coil per Dave Cripe's suggestion.  I think that may help some because the regeneration is screwy.  I am listening to 80m hams at the moment.  No matter where I place the regeneration control, I get no change in volume.  It is as if regeneration is not needed.  There is no regeneration point on the dial at all.  Could it be this quiet?  My only other experience is with the Ocean Hopper.  You could tell when you reached "the point".   Any suggestions anyone?  Thanks, Dale KS4NS

On Mon, Aug 24, 2020 at 1:35 PM Jerome Wysocki <jeromewysocki48@...> wrote:
I found that a generic 2N2222 worked identically well to the Q1 transistor originally in this receiver. Try that, if you have one handy.
On a slightly different related topic, has anyone ever tried substitution of an FET (such as an MPF-102, or equivalent type) for Q1 in this radio? If so, how was it wired, and how well did it work?

... Jerry Wysocki, KC8JXE





--
Dale Hardin
Elberta, AL 

--
Dale Hardin, KS4NS
Elberta, AL


Jerome Wysocki
 

I found that a generic 2N2222 worked identically well to the Q1 transistor originally in this receiver. Try that, if you have one handy.
On a slightly different related topic, has anyone ever tried substitution of an FET (such as an MPF-102, or equivalent type) for Q1 in this radio? If so, how was it wired, and how well did it work?

... Jerry Wysocki, KC8JXE


Curt
 

You can check if the transistor is fubar using dvm on diode.

Curt KB5JO


Dale Hardin
 

Curt, I checked the coil sense---ok.  I even removed the coil and rechecked the tinned ends and replaced the secondary "winding".  Dave Cripe suggested privately that I should just rebuild the entire coil to make sure.  However, I think there is a problem with the new Q1 I installed, so I have ordered more as replacements.  Q1 may be a fake Chinese transistor as it doesn't have gold leads.  So, for now, this project is set aside waiting parts.
--
Dale Hardin, KS4NS
Elberta, AL


Dale Hardin
 

Gwen, I replaced the gimmick cap with a variable cap and fixed cap in series to give me about 0-5pf.
--
Dale Hardin, KS4NS
Elberta, AL


Curt
 

Sometimes regeneration doesn't work because the sense of the coil wilndings is wrong.  Be sure the coil looks line the one in the assembly drawing.  There aren't many parts in the regeneration circuit.

Curt KB5JO


Gwen Patton
 

One thing that might be affecting regeneration is the "gimmick" capacitor C12. You might need more twists or fewer twists. I found it really changes the regeneration level a LOT.

-=-=-=-=-=-=-=-=-
73,
Gwen, NG3P


On Sun, Aug 23, 2020 at 11:22 AM Dale Hardin <joe.dale.hardin@...> wrote:
Thanks Johnny.  I think he is already following this incident.  BTW, this is the rig that a previous ham gave up on in frustration.  You might remember his posts.  I decided to take on the troubleshooting even though I'm not very good at it.  I hope to make it a good receiver for my grandkids.  I got started in ham radio with an Ocean Hopper.

On Sun, Aug 23, 2020 at 9:58 AM Johnny AC0BQ <jomatlock@...> wrote:
Gm Dale
See if you can get in touch with Dave Cripe, NM0S.

His email is NM0S@...

He designed this little bugger, I bet he can get you kick started.

It might be best to email him direct.
Be patient, he is pretty busy.

73
Johnny ACØBQ 



On Sun, Aug 23, 2020 at 9:52 AM Dale Hardin <joe.dale.hardin@...> wrote:
I ran the troubleshooting voltages in the Assembly Manual.  The battery voltage iws 8.434v.  The following voltages are in list order:
0.000
0.889
7.849
0.615
3.454
2.772
4.815
Looks like the voltages on the collectors of Q1 and Q3 are high.  I have gone through the soldering on the regenerative circuit and touched up each one.  Still no regeneration.  I replaced D1, but don't have (or can't find) 1N914 diodes.  Haven't pulled and tested them yet.
Any suggestions?

Regards, Dlae

On Sat, Aug 22, 2020 at 8:07 PM Dale Hardin via groups.io <joe.dale.hardin=gmail.com@groups.io> wrote:
OK, got the little amp installed and working.  After replacing all the transistors, I hooked up my signal injector to the antenna end and got a tone out of the speaker.  However, I do not have any regeneration, so I hooked it up to my antenna.  Still no joy.  Absolotutely no regeneration.  I have the batteries out being recharged so I can get some voltage measurements.  I would appreciate it if one of you more knowedgable members would give me a list of tests to carry out to see what the problem is.  BTW, I removed, checked for good, and replaced the coil, so I'm comfortable it is ok.  The voltage changes on the regen pot when turned, so the pot is ok.  Where do I start looking now?  Dale
 

--
Dale Hardin, KS4NS
Elberta, AL









--
Dale Hardin
Elberta, AL 



--
Dale Hardin, KS4NS
Elberta, AL







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



--
Dale Hardin
Elberta, AL 

--
Dale Hardin, KS4NS
Elberta, AL


Dale Hardin
 

Thanks Johnny.  I think he is already following this incident.  BTW, this is the rig that a previous ham gave up on in frustration.  You might remember his posts.  I decided to take on the troubleshooting even though I'm not very good at it.  I hope to make it a good receiver for my grandkids.  I got started in ham radio with an Ocean Hopper.

On Sun, Aug 23, 2020 at 9:58 AM Johnny AC0BQ <jomatlock@...> wrote:
Gm Dale
See if you can get in touch with Dave Cripe, NM0S.

His email is NM0S@...

He designed this little bugger, I bet he can get you kick started.

It might be best to email him direct.
Be patient, he is pretty busy.

73
Johnny ACØBQ 



On Sun, Aug 23, 2020 at 9:52 AM Dale Hardin <joe.dale.hardin@...> wrote:
I ran the troubleshooting voltages in the Assembly Manual.  The battery voltage iws 8.434v.  The following voltages are in list order:
0.000
0.889
7.849
0.615
3.454
2.772
4.815
Looks like the voltages on the collectors of Q1 and Q3 are high.  I have gone through the soldering on the regenerative circuit and touched up each one.  Still no regeneration.  I replaced D1, but don't have (or can't find) 1N914 diodes.  Haven't pulled and tested them yet.
Any suggestions?

Regards, Dlae

On Sat, Aug 22, 2020 at 8:07 PM Dale Hardin via groups.io <joe.dale.hardin=gmail.com@groups.io> wrote:
OK, got the little amp installed and working.  After replacing all the transistors, I hooked up my signal injector to the antenna end and got a tone out of the speaker.  However, I do not have any regeneration, so I hooked it up to my antenna.  Still no joy.  Absolotutely no regeneration.  I have the batteries out being recharged so I can get some voltage measurements.  I would appreciate it if one of you more knowedgable members would give me a list of tests to carry out to see what the problem is.  BTW, I removed, checked for good, and replaced the coil, so I'm comfortable it is ok.  The voltage changes on the regen pot when turned, so the pot is ok.  Where do I start looking now?  Dale
 

--
Dale Hardin, KS4NS
Elberta, AL









--
Dale Hardin
Elberta, AL 



--
Dale Hardin, KS4NS
Elberta, AL







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



--
Dale Hardin
Elberta, AL 

--
Dale Hardin, KS4NS
Elberta, AL


Johnny AC0BQ
 

Gm Dale
See if you can get in touch with Dave Cripe, NM0S.

His email is NM0S@...

He designed this little bugger, I bet he can get you kick started.

It might be best to email him direct.
Be patient, he is pretty busy.

73
Johnny ACØBQ 



On Sun, Aug 23, 2020 at 9:52 AM Dale Hardin <joe.dale.hardin@...> wrote:
I ran the troubleshooting voltages in the Assembly Manual.  The battery voltage iws 8.434v.  The following voltages are in list order:
0.000
0.889
7.849
0.615
3.454
2.772
4.815
Looks like the voltages on the collectors of Q1 and Q3 are high.  I have gone through the soldering on the regenerative circuit and touched up each one.  Still no regeneration.  I replaced D1, but don't have (or can't find) 1N914 diodes.  Haven't pulled and tested them yet.
Any suggestions?

Regards, Dlae

On Sat, Aug 22, 2020 at 8:07 PM Dale Hardin via groups.io <joe.dale.hardin=gmail.com@groups.io> wrote:
OK, got the little amp installed and working.  After replacing all the transistors, I hooked up my signal injector to the antenna end and got a tone out of the speaker.  However, I do not have any regeneration, so I hooked it up to my antenna.  Still no joy.  Absolotutely no regeneration.  I have the batteries out being recharged so I can get some voltage measurements.  I would appreciate it if one of you more knowedgable members would give me a list of tests to carry out to see what the problem is.  BTW, I removed, checked for good, and replaced the coil, so I'm comfortable it is ok.  The voltage changes on the regen pot when turned, so the pot is ok.  Where do I start looking now?  Dale
 

--
Dale Hardin, KS4NS
Elberta, AL









--
Dale Hardin
Elberta, AL 



--
Dale Hardin, KS4NS
Elberta, AL







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


Dale Hardin
 

I ran the troubleshooting voltages in the Assembly Manual.  The battery voltage iws 8.434v.  The following voltages are in list order:
0.000
0.889
7.849
0.615
3.454
2.772
4.815
Looks like the voltages on the collectors of Q1 and Q3 are high.  I have gone through the soldering on the regenerative circuit and touched up each one.  Still no regeneration.  I replaced D1, but don't have (or can't find) 1N914 diodes.  Haven't pulled and tested them yet.
Any suggestions?

Regards, Dlae


On Sat, Aug 22, 2020 at 8:07 PM Dale Hardin via groups.io <joe.dale.hardin=gmail.com@groups.io> wrote:
OK, got the little amp installed and working.  After replacing all the transistors, I hooked up my signal injector to the antenna end and got a tone out of the speaker.  However, I do not have any regeneration, so I hooked it up to my antenna.  Still no joy.  Absolotutely no regeneration.  I have the batteries out being recharged so I can get some voltage measurements.  I would appreciate it if one of you more knowedgable members would give me a list of tests to carry out to see what the problem is.  BTW, I removed, checked for good, and replaced the coil, so I'm comfortable it is ok.  The voltage changes on the regen pot when turned, so the pot is ok.  Where do I start looking now?  Dale
  --
Dale Hardin, KS4NS
Elberta, AL



--
Dale Hardin
Elberta, AL 

--
Dale Hardin, KS4NS
Elberta, AL


Dale Hardin
 

OK, got the little amp installed and working.  After replacing all the transistors, I hooked up my signal injector to the antenna end and got a tone out of the speaker.  However, I do not have any regeneration, so I hooked it up to my antenna.  Still no joy.  Absolotutely no regeneration.  I have the batteries out being recharged so I can get some voltage measurements.  I would appreciate it if one of you more knowedgable members would give me a list of tests to carry out to see what the problem is.  BTW, I removed, checked for good, and replaced the coil, so I'm comfortable it is ok.  The voltage changes on the regen pot when turned, so the pot is ok.  Where do I start looking now?  Dale
  --
Dale Hardin, KS4NS
Elberta, AL


Curt
 

You could easily unsolder Q3 and test it with your DVM on diode test.  I bought 5 minimodule LM386 amps for $10 delivered.  No constuction just hook them up.

GL n 73, Curt KB5JO


Dale Hardin
 

I'm working on adding that $2 amp.  Darn single sided board with too-small pads is a pain to build.  However, I don't think the amp will solve this rig's problem.  I suspect Q3 is kaput.

On Wed, Aug 19, 2020 at 7:09 PM Curt via groups.io <rhulett1=consolidated.net@groups.io> wrote:
Maybe not relevant:

The stock radio doesn't put out much volume into the speaker.  Headphones worked fine,  I bought a $2 audio amp and wired it into the speaker circuit, now volume from the speaker is very adequate.  I guess the radio was meant to be a retro-style regen and 2 transistors drive headphones fine but a speaker not very well.

72, Curt KB5JO



--
Dale Hardin
Elberta, AL 

--
Dale Hardin, KS4NS
Elberta, AL


Curt
 

Maybe not relevant:

The stock radio doesn't put out much volume into the speaker.  Headphones worked fine,  I bought a $2 audio amp and wired it into the speaker circuit, now volume from the speaker is very adequate.  I guess the radio was meant to be a retro-style regen and 2 transistors drive headphones fine but a speaker not very well.

72, Curt KB5JO


Dale Hardin
 

Thanks.  I'll turn it back around again.  I assume the measurement of Can on Q3 in the Assembly Manual is incorrect.  That's what threw me off.  

On Wed, Aug 19, 2020 at 10:28 AM nm0s_qrp <nm0s@...> wrote:
Hi Dale.  The transformer was marked correctly, and you had it installed properly.  The 5.7 volt level you measured is pretty typical of what you should expect.

73 Dave NM0S



--
Dale Hardin
Elberta, AL 

--
Dale Hardin, KS4NS
Elberta, AL


nm0s_qrp
 

Hi Dale.  The transformer was marked correctly, and you had it installed properly.  The 5.7 volt level you measured is pretty typical of what you should expect.

73 Dave NM0S


Dale Hardin
 

I am working on a troubled Ozark Patrol.  I checked the voltages per the manual and found that the Collector (can) Q3 was 5.72v.  I ohmed out the audio transformer and the marked Primary side was 278.5 ohms and the secondary side was 1.8 ohms.  I reversed the transformer and got  9.25v (battery voltage nearly) at the can of Q3.  Could it be that the "P" was on the wrong side of the transformer?  The rig is still nearly deaf after the change.  I think there may be an issue with the wiring between the transformer-jack- and speaker.  Anyone had a problem with the jack wiring?  I plan to add an amplifier to increase the volume.  The rig has other issues, but I want to resolve this one first.

Dale Hardin, KS4NS
Elberta, AL