bounty hunter VLF-SPD-RB3

[Shuffler]

Picked one of these at a yard sale and don't quite know how to use it...... can anyone explain the adjustment of the tuning and ground balance knobs.? every thing else seems self explanatory........thanks Gene

 

[GoGoGopher]

Hmmm...A Red Baron III ...I will see if I can find a link to a manual for this, unless someone pipes up and says they have one they can scan for ya...


HH,

 

[Shuffler]

thanks for your reply and any info you can provide. i knew someone would recognise this one ........ .........Gene

 

[Ed in SoDak]

I gleaned this from the old BH website which can be found at www.archive.org. This is for the RB5 & RB7, but maybe they are similar enough. No pictures, but you should be able to figure it out without them.
-Ed


NOTE: The following manual was scanned with OCR software. Be aware that there may be a few misspellings or anomalies due to the inaccuracies of the software translation. Images are excluded due to the memory requirements; therefore, there will be references to illustrations that do not exist in this text only document.

 

[ariston]

Hi, just have a problem with one RB3 so, it

 

[Ed in SoDak]

Mine has an LM356N in that location, but in a socket. Hmmm, might be a reason for the socket, like these parts blow frequently? Unfortunately, you will probably also find some shorted transistors nearby that haven't failed to smoke or flying chunks. Which is the case with my RB3 and many other RB models.

The voltage and current from the battery packs are high enough in these units that one bad part can cause a chain reaction that takes others out, so it's a real case of individually test, test test each transistor or IC for shorts and replace as needed, then cross fingers for the powerup test.

There's probably a safer method a tech might use, but I'm not quite a tech, I'm just merely dangerous, LOL! And I've smoked a few more parts learning about this ornery detector.

-Ed

 

[ariston]

Ed in SoDak
Thank you very much
I will try to change it (on a socket)
Off course I will test all around it previously.

 

[Ed in SoDak]

The little blue blobs are tantalum capacitors, I've read where they may be the biggest part of the problem, since they short out inside when they go bad.

-Ed

 

[ariston]

I will test all capacitosr, diodes and transistors near the ic

 

[Detector Tinkering]

I will test all capacitosr, diodes and transistors near the ic

The Red Barons had no reverse polarity protection so if you touch the battery connector momentarily the wrong way you blow the ICs. Detector will appear dead, meter may go full deflection.
Replace all MC1496 ICs & LM358s near them. check/replace +8 volt regulator transistor, it's just below the transmit oscillator circuit.
Replace the tantalums. I have found shorted ones, they don't like reverse voltage or over voltage but have no age related failure mode so are a good choice if used properly.
I have installed diode protection in the form of surface mount diodes across the power rails where battery power is fed to the board. I would recommend this before plugging in the battery packs or you might blow all your new chips.
Hope this helps
Regards