Bounty Hunter Outlaw TR/BFO

TR requires two coils.   I'm thinking the little coil is for BFO only.

Have you tried to Null the Big Coil with the Tune knob?

Start with it centered  Discrim control in the Off Position :

If the Meter goes right, Turn the Tune control Left.

If the Meter Goes Left, Turn the Tune control Right.

Amuse me and Try it!  LOL!  

 

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When the Big 6" x 12" coil is attached, I am unable to null out the tone, it is continuous. Whether I turn the Null Knob left or right doesn't make any difference. This happens whether the unit is in TR or BFO mode. I understand that this unit is a hybrid. I am able to use the small 6" coil in either TR or BFO mode and tune it (nulling out the tone/clicks), with Discr either on or off..

Both coils have connectors with 4 pins and a threaded body which acts as ground. The cable on 6" coil is RG-58 A/U with single center conductor and shield / braid. The cable on 6x12" coil has two center conductors with shield / braid.

The pins on the 6" coil connector are as follows
Pin 1 - Body
Pin 2 - N/C
Pin 3 - Center Conductor and resistor connected to ground
Pin 4 - N/C
Body - Braid

Pins on 6"x12" coil connector:
Pin 1 - N/C
Pin 2 - N/C
Pin 3 - White center Conductor
Pin 4 - White center Conductor
Body - Braid

Attached are photos of both connectors.

My general impression is that if there is nothing wrong with the coils or their connections, there may be something wrong with the Induction Balance Circuit inside the detector box. My guess is that the IB circuit operates when the 6x12 coil is used, but not the 6"coil. It's my guess also that pin #4 on the 6x12" connector is part of the IB circuit?

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The detector works with the smaller 6" coil installed and the switch set to BFO -or- TR. The 6" coil has two connections, Pin 3 and Ground. If TR requires two coils (with three connections) I don't know how that would be possible. In any case, HomeFire.. Yes, 3 & 4 are shorted.

Well, I guess that means the coil is bad. Logically, for any purpose there would be no reason for the two pins to be shorted. I guess I can be adventurous and see if I can disassemble the bottom covering (without destroying it) and see if I can trace the short. Do these coils sometimes have a component inside the casing that could short? Or.. is it more likely that the coil has very fine wire that may have corroded due to exposure to moisture and shorted.. or both? The underside of the plastic coil housing has a long crack which someone in the past had tried to seal up.

Thanks for your assistance. What are the next possibilities?

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Thanks again. I will try your idea of reterminating the cable.

Another possibility? (and you're testing my electronic competence here.) There are two coils in the big 6x12" coil, and they have a common ground in the connector. I would assume that the two coil circuits would have to be electrically isolated from each other, otherwise there would be a short. Is it possible that there is a non-electrolytic capacitor in the coil housing used for this purpose, and that could have shorted? Otherwise, why wouldn't the manufacturer just use another pin on the connector to isolate them by using three conductor cable instead of two?

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Thanks for your continued assistance.

I haven't reterminated the connector.. yet, but I was able to remove the underside plastic cover from the large Triple coil without damaging the coil itself. The plastic was cracked and can be replaced easily with something else. The coil itself from the underside looks like a 3 layer printed circuit, not single strands of wire. There are two solder connections with thin wire which appear like they are electrically connected to the same copper plate. I can't tell if they are the same conductors which are soldered at the connector end as I haven't been able to remove the coil itself from the housing to trace them. The coil PCB is glued to thick paperboard, which is then glued to the upper half of the housing. The coil doesn't seem to be damaged See attached

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