Help/Advice for SCR-625-C Mine detector

[Lazzari]

Hello.
I hope you can help me I have a U.S army mine detector SCR-625 C 1944 dated.
My problem is I am trying to get it to work (There is no manual with the item) it needs 2 BA-30 batteries and 1 BA-38 battery.
If anybody can point me in the right direction of help or a shop or anything I would be very obliged.
I appreciate you taking the time in reading this mail.
Many Thanks
Brian Lazzari

[Station X]

GIYF. Google Is Your Friend.

BA-30 ia a 'D' Cell.

For BA-38 see here:-

http://www.smallbattery.company.org.uk/sbc_ba38.htm

Manual here:-

http://www.military-info.com/Index.htm

and probably elsewhere if your search round.

[Lazzari]

Rather than spending £100 (In case it needs more TLC than batteries) on a battery would it work if I wire a few batteries in series to get near the 103.5v

[Darren-UK]

You could do what we do when needing to power battery/valve radios; series-connect some 9v PP3 batteries. Eleven of these will give you 99v which should be adequate, or you'd probably get away with twelve which will give you 108v. If you scout around the pound-shops, this shouldn't cost you much more than a tenner.

Unfortunately the BA-38's dimensions are a few millimetres too small to allow you to make up a power pack in this way and insert it inside the instrument. You'd therefore need to somehow connect it externally to test the instrument, then proceed from there if all is ok (or otherwise).

[Mike-repairman]

By my calculations (just having measured a PP3 battery) you should just be able to make up a pack of 12 x PP3 9V batteries putting two side by side and 6 in a row end to end. I can't see a problem with running it at a few extra volts.

PP3s are approx 17.5mm thick but removing the outer casing (which you would probably do anyway) and wrapping in insulation tape should bring the width of two down to near 34.1mm as in the spec on SBC site.

I'd be surprised if the battery box area was that tight anyway, so removing the outer casings of the PP3s may be unnecessary.

Mike.

[Station X]

Brian.

As you say the device may need more than batteries to get it working. Before going to the trouble of making a replica battery to fit in the battery compartment you could just plug together 11 PP3s and connect them via flying leads.

I know nothing about this device, or your level of expertise. I would suggest the first thing to to is insert the 'D' cells, switch on and check if the valves light up. In common with other military gear of the period it will probably need any wax paper or Hunts type capacitors replaced. I'd be inclined to check the continuity of the search coil(s) too.

[batterymaker1]

Here's what you need for the HT battery:

http://solo11.abac.com/zorroab1/BC-611%20Box.htm

[Ed_Dinning]

Hi Lazzari, it would pay to check the coils in the search head are not open circuit first. A normal ohm meter should do this.
I have seen this problem with British mine detectors and as the coils are totally potted they could not be re-wound.

Ed

[quartercav]

Brian,
I am an electronics tech and I have fixed 7 SCR-625s for myself and others. I have a website of sorts at http://sites.google.com/site/scr625/Home. Still under construction, hope it works. The chief issue is that of a battery, which others have replied to, and changing out a number of capacitors. Replacing capacitors 17 and 14-2 will get you a 50% chance of a detector that will detect to six inches, maybe more if you are lucky. 17 should be .012ufd and 14-2 should be 470 pf, about 200V rating. After detailed repairs, I can usually get one to detect at just over one foot. Look over the insides well before you go spending any money on it.
Dewey