Compass Depth Doubler

[Darren]

I know some of you will remember this gadget. I don't remember the exact area it covers, but I know you drive stakes in the ground, attach a 12V battery and use any detector to get better depth. It got great reviews. They are still being sold for hundreds of dollars by those who bought them back in the late 80s and early 90s.

Anyone know the basic design? Is there a simple way to make one with a control box, a few stakes and wire?

[Carl-NC]

Re: Compass Depth Doubler

I have 2 of them. The design is basically a switching power supply, built around the Linear Tech LT1270. The idea is that the 24v output will "charge" the ground and enhance target signals, resulting in greater depth.

Does it really work? Dunno, I haven't tested mine yet. I bench-tested the first one I bought just to see what it would do, and it did not seem to operate as the design suggested it should, so I assumed it had problems. I recently procured a second one, but haven't checked it out.

- Carl

P.S. -- you could build one for $20 or so.

[Darren]

Re: switching power supply

I am not that familiar with switching power supply, but I am willing to learn by experimenting. Do you recommend a switching power supply that is readily available? The Linear Tech LT1270 doesn't seem to be easy to get.

Thanks, Darren

[Carl-NC]

Re: switching power supply - Depth Doubler

The LT1270 is available from Digi-key, but at $10 it's a heap more money than I expected.

Over the weekend, I plugged up my second unit, and with an input of 12v, the output was... 12v. That ain't right. So I went back to the first unit, and the output was 24v. But the o-scope shows it to be mostly DC, with just a slight amount of a partial ramp riding on it.

I guess that, when I first looked at it, I expected to see some amount of a pulsed signal, but maybe all this thing is, is a 24v DC source. If so, then any design that produces a high DC voltage (including 2 12-volt batteries in series) will do. The only thing to watch for, is the amount of current needed, especially at initial turn-on.

- Carl

[Sean Goddard]

Re: switching power supply - Depth Doubler

This device was NOT made by Compass, it was made by some shyster calling himself (illegally) Compass in the USA.

The individual involved is still on the FBI wanted list, and is believed to be in Japan somewhere.

The unit never worked, though the principle is sound enough. Should have been a pulsed system Carl (as you said) but ended up being a DC output as the guy who designed it didn't know what he was doing.

Compass in Oregon do not support, or recognise this unit as a Compass product.

[Carl-NC]

Re: switching power supply - Depth Doubler

>This device was NOT made by Compass, it was made by some shyster calling himself (illegally) Compass in the USA.

Yup, I should have mentioned this. The real Compass had nothing at all to do with the Depth Doubler, though I've never found out exactly who was behind making it. I do recall that Larry Williams, who used to publish the Treasure Hunter Confidential newsletter, was involved in the early stages of the Depth Doubler, so he would know.

The bogus Compass also made the "Gold Cross", which was a long-range locator, and sold by Kellyco. Kellyco still sells the same device, though they don't advertise it as a "Compass" anymore. But you can still see the "Compass" logo in the pic on their web page.

Interestingly, Kellyco was also a major seller (perhaps the only seller) of the Depth Doubler. Given Kellyco's history of selling bogus crap, some of which they very likely produced, it wouldn't surprise me if they are knee deep in the bogus Compass scheme.

- Carl

[Agraz]

I have a 24 volt DC battery charger, Sunrise SBC24-02B5L and has inside a switched power supply with the IRF840B, i try putting electrodes and power this charger with a voltage inverter,,, I think that any charger could energize the earth in some way:

https://thea.com/Parts-Accessories-Scooter-Battery/

[Melbeta]

yes, I knew that the Depth Doubler was not a Compass product. Neither was the pin pointer. I do have one of them, did a good test with it. It works better when the ground is wetter then dry. I do not believe they did pulse, but the old pulsed worm units, brought the worms right up out of the ground. On my tests I did find some old targets. But I do not know if it was because the ground was engerized or just because I was digging up almost all targets. The park I was testing with it was created in 1900, and I have photos of the park area showing horse and buggies and later old time cars. It was a railroad park next to the railroad depot.
Melbeta