Older style IB/TR: obsolete or not?

[André]

Are older style IB /TR detectors really obsolete? I am convinced that some TR detectors of the mid and late 70's like the White's Beachcomber 4, the C-Scope TR 400 or the Heathkit GDA 348 (and some other TR detectors) are not as bad as some forum participants claim. Recently, my 20 year old White's Beachcomber 4 outperformed a Minelab Sovereign XS Pro in the most difficult ground conditions (highly mineralised and iron infested soil)!!!! Modern motion detectors are very comfortable to use. They are able to work in highly mineralised areas, have good iron discrimination (e.g: Tesoro), but are affected by target masking caused by small iron parts: they are unable to detect a 1.1 cm coin lying under a 6 cm iron nail whereas older IB/TRs are able to do so! (NB: a sole nail is rejected by a decreasing threshold tone.) Older style TR detectors may not detect as deeply as modern VLF/TR motion detectors, but scan the first 10 cm more accurately (= miss less tiny non-ferrous items) than VLF motion machines! VLF/TR motion detectors, even if well ground balanced, don't go much deeper than older IB/TRs in difficult soil conditions!


I have tried many "deep seeking" motion machines (Fisher 1266 X or CZ-5; White's Spectrum, Minelab Sovereign XS Pro,…), but none achieved better my detecting purpose (detecting tiny non ferrous items in the most difficult ground conditions) than my old BC 4. Only problem of TR non motion detectors: searching in a very roughly ploughed field produces many false signals...

[Carl]

From what I continue to read on MD forums the old Compass detectors are the ones to beat for use in nail-infested areas. I've been on the lookout for one at a good price.


- Carl

[Sam Scafferi]

>From what I continue to read on MD forums the old Compass detectors are the ones to beat for use in nail-infested areas. I've been on the lookout for one at a good price.


>- Carl


You are absolutely correct, Carl. One of my many detectors was a Compass, forest green in color, and a white coil. Very nice machine, and was easy to ignore nails and bottlecaps. (Oh dear, I mentioned bottlecaps... did that date me??) I don't have that machine anymore, but it was featured in an article I wrote on coinshooting, which appeared in Treasure magazine, Oct. 1973, Vol. 4, No. 10. ...for those of you who want to go through your old magazines and look it up. My copy is getting a little yellow, and I have to handle it rather carefully.

[André]

Carl,
In some MD forums I also read that older Compass detectors were nearly unbeaten in difficult ground conditions, so I ordered a Compass Yukon 77-B professional from the USA. I tried it once in a field with extreme soil conditions (Roman bricks, nails,...): it worked well (smooth threshold). Even if it's threshold tone (ground adjust set at a low degree)is good, I prefer my old White's BC 4. In some difficult ground conditions however I would like to have a ground adjust on my BC4 like the one of the Yukon 77.
My question to the electronic specialists: Is there anyone who can tell me how to add such a ground attenuator to my White's BC 4? As far as I was told, the sensitivity of the receiver part has to be reduced a little bit with a potentiometer. NB: I can't get the electronic schematics of the BC 4 from White's Electronics as the BC 4 is still manufactured in Inverness/Scottland/
Europe. The headphones that match the best ancient BC4 detectors are the HD-414 from Sennheiser, built about 20 years ago. The new HD 414 (anniversary edition of the HD 414) have not the same specifications as the old one.
André




>From what I continue to read on MD forums the old Compass detectors are the ones to beat for use in nail-infested areas. I've been on the lookout for one at a good price.


>- Carl