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Ozark Patrol


Larry Draughn
 

Looking for a little trouble shooting a Ozark Patrol I am building an have it complete, problem is Low voltage on Q1 can  (3.5 v) and Q3 can (5.5v) any help would be appreciated tnx Larry 


wa2cky
 

Yep, you have a problem. I am not familiar with Ozark Patrol but looking at the schematic and knowing that the can's on 2n3019's are the collectors, there is a big problem someplace. Do NOT run very long (i.e. seconds - just to take readings).  You need to double check your wiring and the orientation of the transistors. Q3's collector (can) should be at +9V (i.e. direct connection to the battery + terminal through T1's primary. Q3's emitter should be (a guesstimate on my part) a couple of volts and Q3's base would be 0.6V above that. Q2's emitter is grounded, the base would be 0.6 V or so and the collector is equal to Q3's base (Q2 and Q3 are a simple audio amplifier with feedback to set the operation point.   A shorted or 'installed backwards C10 should be checked for. 

In no scenario should Q3's collector be anywhere other than +9V!!!

Q1E should be zero voltage.
Q1B should be at about 0.6 volts
Q1C should be at (a pure guess on my part) at +4V (so maybe ok??)

Anyways that is my guess and stab. Probably get some better info from others. Again I suggest a careful check of the circuit including the transistor wiring, electrolytic cap polarity, etc.

73
Bob Groh, WA2CKY 

On Fri, Feb 19, 2021 at 12:55 PM Larry Draughn <ldraughn@...> wrote:
Looking for a little trouble shooting a Ozark Patrol I am building an have it complete, problem is Low voltage on Q1 can  (3.5 v) and Q3 can (5.5v) any help would be appreciated tnx Larry 


W0PWE
 

Hi Larry. I would agree with Bob's assessment. I was just working on an Ozark Patrol RX last night so I have the schematic handy.  3.5V on Q1 collector is on the low side but within the range specified in the troubleshooting section of the manual.  If you have 5.5V on Q3 collector then you must have something drawing a lot of current and likely pulling your battery voltage down. I don't think it is this but I'm going to ask - you don't have the battery connected backwards do you? Notice that the ON/OFF switch switches the negative side of the battery to ground. 

A bad or backwards C7 could also pull your battery voltage down. 
73
Jerry - W0PWE