Topics

problem with my 4SQRP Ozark Patrol Radio

Curt
 

Just for info, my radio (which works) has following readings

On Mon, Jun 1, 2020 at 09:59 AM, n5ib_2 wrote:
1) battery voltage, at the battery +terminal, or at the top of R1 = 8.6VDC

2) voltage at the junction of R1 and R2, or at the + lead of C3 = 7.9

3) voltage at the top of the regen pot, or + terminal of C13 = 7.85

4) voltage at the junction of R3 and the regen pot (other end of the pot) = 3.64
... also check that this voltage decreases as you swing the regen pot through its range towards full clockwise
... then put the pot back to full counterclockwise for the rest of these checks

5) voltage at the R3 / R10 junction, or the base of Q1 = 0.53
Curt KB5JO

n5ib_2
 

Hi Herb,

I'm presuming you've fixed the earlier problem of low voltage on the Q3 collector?

Before replacing any more parts, do a little voltage detective work for us. This will give some clues as to whether the problem is Q1 itself, or its biasing circuit. With the regen pot fully counterclockwise (minimum resistance, maximum regeneration) measure the following with respect to ground (record the full resolution of your voltmeter):

1) battery voltage, at the battery +terminal, or at the top of R1

2) voltage at the junction of R1 and R2, or at the + lead of C3

3) voltage at the top of the regen pot, or + terminal of C13

4) voltage at the junction of R3 and the regen pot (other end of the pot)
... also check that this voltage decreases as you swing the regen pot through its range towards full clockwise
... then put the pot back to full counterclockwise for the rest of these checks

5) voltage at the R3 / R10 junction, or the base of Q1

The too high voltage at Q1 collector could be due to a short to ground at the base of Q1, or it couod be due to an open circuit in its base bias circuit. The above measurements ought to narrow it down.

Now, if you have time... temporarily unsolder and lift the base lead of Q1 and repeat the measurements above. For (5) above probe the PCB pad for the base of Q1 , not the base lead itself.

Neither a backwards nor forwards D2 and/or D3 would short Q1-B to ground unless *both* diodes were shorted.

Jim, N5IB

John Lonigro
 

Just thinking out loud here, but what if both D2 and D3 were installed backwards?  I don't have an Ozark Patrol.  I'm just relying on Curt's observations.

72,
John, AA0VE

On 6/1/20 6:28 AM, Curt via groups.io wrote:
Herb

No voltage on Q1 base implies short to ground in that circuit.  Absent an internal B-E short, the voltage should be at least 1/2V across D2 and D3.  Since you have replaced that transistor, the other possibles would be BOTH D2 & D3 shorted ( not likely ), R10 (not likely), or C4 ( possible but not likely ).

Did you ever try headphones? 

Am at a loss. Sorry.

Curt

Curt
 

Herb

No voltage on Q1 base implies short to ground in that circuit.  Absent an internal B-E short, the voltage should be at least 1/2V across D2 and D3.  Since you have replaced that transistor, the other possibles would be BOTH D2 & D3 shorted ( not likely ), R10 (not likely), or C4 ( possible but not likely ).

Did you ever try headphones? 

Am at a loss. Sorry.

Curt

Jerome Wysocki
 

Hi Herb,
The fact that it squeals seems to indicate the audio section is at least working. Not quite sure why voltages around Q1 are not right, so for some reason the problem seems to gravitate there. For Q1, I tried replacing it with a 2N2222, and that worked fine for me, but still your incorrect voltages around Q1 gets me wondering.
... Jerry Wysocki, KC9JXE

Herb Parsons <radioherb@...>
 

Curt,

I get nothing from the speaker except slight noise as you turn the volume control up and down. If I touch my fingers from Q1 collector to Q3 collector, I get a loud squeal from the speaker. I double checked all parts placement and polarities. I've replaced all the transistors. I checked all the voltages listed and all were OK except the voltages on the collector of Q1 is 7.8 volts and the base reads 0 volts. I even removed L1 and reversed it. I would love to get this radio to work. I have made quite few tube regens, but this my first transistor regen set. Do you have any suggestions as to where I should go from here? Thanks so much for anything you might suggest.
   
Herb Parsons


-----Original Message-----
From: Curt via groups.io <rhulett1@...>
To: main <main@4SQRP.groups.io>
Sent: Sun, May 31, 2020 4:30 pm
Subject: Re: [4SQRP] problem with my 4SQRP Ozark Patrol Radio

Herb,

Any progress getting the radio to function?

Curt KB5JO

Curt
 

Herb,

Any progress getting the radio to function?

Curt KB5JO

Johnny AC0BQ
 


Gm Guys
Hope your all have a Safe Memorial Day.
Just FYI,
Dave Cripe NMØS designed the Ozark Patrol.
72
Johnny ACØBQ 


On Sun, May 24, 2020 at 12:50 PM Herb Parsons via groups.io <radioherb=aol.com@groups.io> wrote:
Thanks Jerome!

Herb


-----Original Message-----
From: Jerome Wysocki <jeromewysocki48@...>
To: main <main@4SQRP.groups.io>
Sent: Sun, May 24, 2020 1:33 pm
Subject: Re: [4SQRP] problem with my 4SQRP Ozark Patrol Radio

Hi Herb,

Try melting and re-flowing the solder on each of the solder pads, one lead at a time for each component, then recheck your voltages. Before doing this to the torroid coil windings, measure their resistances first with an ohm meter. You might have a cold solder joint on one or more of these coil wires, due to the fact that there is transparent enamel insulation around these wires. You undoubtedly carefully scraped off this enamel insulation, but it could be deceptive. It is possible that solder flowed around, but did not stick properly to the wires. I had this happen and had to re-solder mine as such. Visual examination did not reveal the problem, so I carefully tinned the wires and when this appeared ok, I re-soldered the coil back on to the board. This time I had success, and my set worked.

Keep us up to date on your attempts to get your receiver going. Hope you get yours up and running soon.

73s

Jerry Wysocki, KC9JXE


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

Herb Parsons <radioherb@...>
 

Thanks Jerome!

Herb


-----Original Message-----
From: Jerome Wysocki <jeromewysocki48@...>
To: main <main@4SQRP.groups.io>
Sent: Sun, May 24, 2020 1:33 pm
Subject: Re: [4SQRP] problem with my 4SQRP Ozark Patrol Radio

Hi Herb,

Try melting and re-flowing the solder on each of the solder pads, one lead at a time for each component, then recheck your voltages. Before doing this to the torroid coil windings, measure their resistances first with an ohm meter. You might have a cold solder joint on one or more of these coil wires, due to the fact that there is transparent enamel insulation around these wires. You undoubtedly carefully scraped off this enamel insulation, but it could be deceptive. It is possible that solder flowed around, but did not stick properly to the wires. I had this happen and had to re-solder mine as such. Visual examination did not reveal the problem, so I carefully tinned the wires and when this appeared ok, I re-soldered the coil back on to the board. This time I had success, and my set worked.

Keep us up to date on your attempts to get your receiver going. Hope you get yours up and running soon.

73s

Jerry Wysocki, KC9JXE


Herb Parsons <radioherb@...>
 

Thanks again Curt!

Herb


-----Original Message-----
From: Curt via groups.io <rhulett1@...>
To: main <main@4SQRP.groups.io>
Sent: Sun, May 24, 2020 1:41 pm
Subject: Re: [4SQRP] problem with my 4SQRP Ozark Patrol Radio

"I even removed L1 and reversed it"
Be sure to put the toroid back as shown in the build manual.  If the "sense" for the one-turn tickler is wrong the regeneration won't.  So trying to correct low volume through the speaker, changing L1 may have produced lots of hiss in the headphones but no RF gain ( regeneration ).  Also, a gimmick of about 1" twist was good for me using the station antenna.

BTW, whoever designed and kitted this radio did a first class job, this regen receiver worked right off of the build table, unlike some others I have built.  Especially if the description has "high performance" in the name, I had poor results.  Like my dear old Dad always said, better to under promise and over perform than the other way around.

Curt KB5JO

Curt
 

"I even removed L1 and reversed it"
Be sure to put the toroid back as shown in the build manual.  If the "sense" for the one-turn tickler is wrong the regeneration won't.  So trying to correct low volume through the speaker, changing L1 may have produced lots of hiss in the headphones but no RF gain ( regeneration ).  Also, a gimmick of about 1" twist was good for me using the station antenna.

BTW, whoever designed and kitted this radio did a first class job, this regen receiver worked right off of the build table, unlike some others I have built.  Especially if the description has "high performance" in the name, I had poor results.  Like my dear old Dad always said, better to under promise and over perform than the other way around.

Curt KB5JO

Jerome Wysocki
 

Hi Herb,

Try melting and re-flowing the solder on each of the solder pads, one lead at a time for each component, then recheck your voltages. Before doing this to the torroid coil windings, measure their resistances first with an ohm meter. You might have a cold solder joint on one or more of these coil wires, due to the fact that there is transparent enamel insulation around these wires. You undoubtedly carefully scraped off this enamel insulation, but it could be deceptive. It is possible that solder flowed around, but did not stick properly to the wires. I had this happen and had to re-solder mine as such. Visual examination did not reveal the problem, so I carefully tinned the wires and when this appeared ok, I re-soldered the coil back on to the board. This time I had success, and my set worked.

Keep us up to date on your attempts to get your receiver going. Hope you get yours up and running soon.

73s

Jerry Wysocki, KC9JXE

Herb Parsons <radioherb@...>
 

Thanks Curt!
Herb


-----Original Message-----
From: Curt via groups.io <rhulett1@...>
To: main <main@4SQRP.groups.io>
Sent: Sun, May 24, 2020 8:37 am
Subject: Re: [4SQRP] problem with my 4SQRP Ozark Patrol Radio

Have you tried the radio with headphones?  The volume available from the speaker without more amplification is underwhelming.  I added one of those cheap $2 amplifiers to increase the volume through the speaker.

Curt KB5JO

Herb Parsons <radioherb@...>
 

Thanks! I'll check it out when I get back, the 1st week in June. 


-----Original Message-----
From: Jess Gypin <ontarget1911@...>
To: main <main@4sqrp.groups.io>
Sent: Sun, May 24, 2020 10:06 am
Subject: Re: [4SQRP] problem with my 4SQRP Ozark Patrol Radio

You don’t get much volume at all out of the speaker. Yes headphones. And try a couple of different ones if you have them. I also added an audio amplifier.

Jess AE0CW

On May 24, 2020, at 6:37 AM, Curt via groups.io <rhulett1@...> wrote:

Have you tried the radio with headphones?  The volume available from the speaker without more amplification is underwhelming.  I added one of those cheap $2 amplifiers to increase the volume through the speaker.

Curt KB5JO

Jess Gypin
 

You don’t get much volume at all out of the speaker. Yes headphones. And try a couple of different ones if you have them. I also added an audio amplifier.

Jess AE0CW

On May 24, 2020, at 6:37 AM, Curt via groups.io <rhulett1@...> wrote:

Have you tried the radio with headphones?  The volume available from the speaker without more amplification is underwhelming.  I added one of those cheap $2 amplifiers to increase the volume through the speaker.

Curt KB5JO

Curt
 

Have you tried the radio with headphones?  The volume available from the speaker without more amplification is underwhelming.  I added one of those cheap $2 amplifiers to increase the volume through the speaker.

Curt KB5JO

Herb Parsons <radioherb@...>
 

Gentlemen,
I recently purchased and built one of your 4SQRP radios (a great kit!). I am having a problem getting it to work. Johnny Matlock suggested I join your group to get some help.  I get nothing from the speaker except slight noise as you turn the volume control up and down. If I touch my fingers from Q1 collector to Q3 collector I get a loud squeal from the speaker. I double checked all parts placement and polarities. I checked all the voltages listed and all were OK except the voltage on collector if Q3 is only 5.1 volts. I even removed L1 and reversed it. I would love to get this radio to work. I have made quite few tube regens, but this my first transistor regen set. Do you have any suggestions as to where I should go from here? Thanks so much for anything you might suggest. I've attached a photo of my set.
   
Herb Parsons