Re: Ozark Patrol help needed


Not familiar with Ozark Patrol (I might have to get one to play with) but here are my thoughts:
1.  The base bias on Q1 is a bit low but probably not a problem at this point. Does V(Q1b) vary with the REGEN control (R4)?  

2.   I would check the voltage along the component chain leading to Q1 - i.e. junction of R1 and R2, R2 and L1a. 

If Q1 was 'off' the voltage on Q1c would be a bit less than battery voltage. You are reading 0V so it, as Mike commented, sounds like you either have a short on Q1c or a lack of continuity somewhere along the string from the battery to Q1c. 

So just keep looking at voltages and staring at the schematic. Something is amiss - probably a bad solder joint. Good luck!  

Bob Groh, WA2CKY

On Sat, Aug 26, 2017 at 8:47 AM, dv1900@... [4sqrp] <4sqrp@...> wrote:

My son has just completed the Ozark Patrol kit, however it doesn't appear to be working properly.  When we power it on, there is a slight hiss from the speaker, however turning the regen knob or tuning knobs doesnt really change anything.  

Moving on to the voltages listed in the instructions this is what I measured:

Battery voltage - 9.35 volts

I will put the voltage listed in the instructions in parentheses at the end just for reference

Emitter Q1 - 0v (0v)

Base Q1 - .52v (.65v)

Collector Q1 - 0v (3-5v)

Base Q2 - .61v (.65v)

Collector Q2 - 3.41v (3v)

Emitter Q3 - 2.74v (2.5v)

Collector Q3 - 5.48v (8-9v)

Ok, so something is clearly wrong on collector of q1 and collector of q3 ... the others seem close to me.  Looking at the schematic, I measured the voltage before R1 (around 9v) and between R1 and R2 (around 4.5v), but then the voltage drops to 0.

I have looked at the basic stuff (correct components and diode orientation / cold solder / bridges - that's not to say I didn't miss something), but I was wondering if anyone might have any suggestions on where to focus my attention.


Dan (KF5CSO)

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