Bounty Hunter Red Baron VLF/SPD

Hey!   Jump over to User introductions and say Hi to folks would ya?

I have a copy of the RB 7  three board.   It may have some common ground.



Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,22495.msg158673.html#msg158673

I think there all pretty much the same detector circuit boards wise.  Some may be populated with more goodies and options.

If you need the Schematic just PM me and I'll send what I have.

 

They use a Weird power supply set up. 

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,22495.msg159047.html#msg159047

Received the RB7 info.  It has been around the world and back. What a HOOT!

I've spent a couple of days checking the diagrams against the boards. So far they have matched up precisely.

The power voltages seem OK +/- 11.2 volts and +/- 7.6 volts.

My problem seams to be the Local Oscillator output is only about 0.3 volts p-p (the diagram depicts 8-11 volts p-p).  The local Oscillator doesn't run with the Search Coils unplugged, I've assume that the Search Coils form a Tank Circuit for the Oscillator!

The Search Coils seem to test OK each coil is about the same resistance, this could be a Red Herring as there may be some short circuit turns.

Can anyone help with the following questions:
1.) Are the Search Coils part of the Oscillator?
2.) How can I test the Search Coils more thoroughly.

Any comments and help will be greatly appreciated as I would prefer not to scrap the Beast.

Old Hat.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,22495.msg161822.html#msg161822

Thanks for the tips.

They helped me find "MY" trouble, my CRO (1966 vintage) need a good dose of de-watering spray around the input attenuator.  Wow what a difference that has made I can see waveforms allover the place with a bit  of logic about them. Bugger Burrer.

I now find that the Local oscillator is 6 volts p-p (clean looking sine wave) at the transmitt coil.

There is 50 Milli volts on the outputs of the receive coil and bases of the preamp transistor bases (again clean looking).  The Transistor bases have the same wave form. The collector waveforms are a horrible looking mess (1/2 of the wave is smooth the other 1/2 has a very fast rise time in all it would seem if the transistors are acting as a frequency doubler or harmonic generator!!).  The +/- 8V to the transistors is OK, the resistors check OK, the collector capacitor seems to be doing it's job: disconnecting it makes the wave forms worse.

Can any one comment on the action of the preamp the collector has -2.9 volts, the base +80mili volts and the emitter +.75 volt.

I will appreciate any help or comments.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,22495.msg162062.html#msg162062

Hello Homefire I see you are always helping someone.That was quick the schematics from you to Oldhat .Mine took ages it must have been the floods we had at that time.Is nice to see another Red Baron Problem
Oldhat if you give up on it I will take it where in Australia are you.I have fixed the one board model that was a nightmare due to the previous owner trying to fixed it.And a couple after that of the three Rat's next model that you have to fight your way through all the wires.Does every thing work other then the ground balance on yours.Because so far the ones I have looked at was the power wiring,due to like Homefire says power set up.Some people can get the power packs sot hey stick two nine volt batteries or the packs are so tight they touch the positive to the frame of the control box.It's a good idea to put a fuse on the power leads.I'm not sure if I have talked to you about mine Oldhat.But have you finish yours fault or problem wise?One simple but you never know if you have not have you checked the three ball bearings in the ground control pot,are they moving freely are you getting any change when turning them,sometimes they seized with no used it and you think you are adjusting but all you are moving is the dial.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,22495.msg169549.html#msg169549