Metrotech 220 surgery

[trukedd]

Thanks to the Forum and especially Forum Member 'Fish N Chips' the old girl is now fully functional and up and running and in perfect health and will be outstanding in her chosen field, Here is a picture of her sleeping it off after the minor surgery of reconnecting the brown wire that had become disconnected.

 

[Tom_in_CA]

thanx for the update. Do us/me a favor, and report the following results: How deep can it find a USA dime to ? Like an air test for start. And then an in-ground test (moist ground that you can re-pack/stomp to the same denisity, etc....).

I've heard those metrotechs could get a dime to a respectable 5" or so (not back for the early 1960s!). But can you confirm that with yours ? thanx.

 

[jtalley007]

I didn't get one because they‘re coils weren't shielded. Grass drove you nuts. Happy hunting

 

[trukedd]

thanx for the update. Do us/me a favor, and report the following results: How deep can it find a USA dime to ? Like an air test for start. And then an in-ground test (moist ground that you can re-pack/stomp to the same denisity, etc....).

I've heard those metrotechs could get a dime to a respectable 5" or so (not back for the early 1960s!). But can you confirm that with yours ? thanx.

Hi again Tom, I am in Cheshire, England and do not have a dime! However I have made an air test with an english 2 pence coin, these are made of steel and copper coated. I can only get this coin to air test at 4 inches. As this old girl is a collectors item and in pristine condition I am not going to use her in the field, however a ground test would be useful to us both. I will post my findings at a later date.

 

[Tom_in_CA]

Hmm, a steel coin ? Can you also test a conductive coin too (copper or silver for instance) that approximates the size of a USA dime. thanx

 

[Fish N Chips]

Very nice trukedd. Yours looks like new! Mine has been used hard. My grandpa used it a lot at schools and old mining camps. I went to fire mine up after taking the pictures and found I need to clean the potentiometer again. I use a cloth and some alcohol and it seems to clean up well. I may end up just replacing the potentiometer with a newer version.

I used this unit quite a bit when I got it from my grandpa 25 years ago. I used it at an old cabin close to me and found a lot of junk and a couple goat/sheep bells, some Model A parts, ect. I did not find many coins but seem to remember it getting down 4 inches on coins. My grandpa got a lot of coins at the school he hunted and I want to say he averaged 3-4 inches? I think he got some silvers pushing 5", but am not sure. If I get the chance to clean it up I will try it out on some US coins and see what depth I get. I know it will go deeper on relics. If I were to use it for any amount of time, I would need to rig up a sling to support the weight.

 

[trukedd]

Hi again Fish N Chips. Yes she looks well on the outside and again thanks to you on the inside also. I have heard that using the Metrotech backwards with the control box behind the little finger instead of in front of the thumb helps with the weight, I have not tried this myself because i am not using it for any appreciable amount of time. Have you any experience of this method of using yours this way ?.

 

[Fish N Chips]

I have not tried it backwards but it makes sense. I will have to try that. I did wrap a dog leash around it one time to use as a shoulder strap. It worked well as long as it was set long enough.

 

[trukedd]

thanx for the update. Do us/me a favor, and report the following results: How deep can it find a USA dime to ? Like an air test for start. And then an in-ground test (moist ground that you can re-pack/stomp to the same denisity, etc....).

I've heard those metrotechs could get a dime to a respectable 5" or so (not back for the early 1960s!). But can you confirm that with yours ? thanx.

Hi again Tom, I am in Cheshire, England and do not have a dime! However I have made an air test with an english 2 pence coin, these are made of steel and copper coated. I can only get this coin to air test at 4 inches. As this old girl is a collectors item and in pristine condition I am not going to use her in the field, however a ground test would be useful to us both. I will post my findings at a later date.

Hi Tom. I have found a Bronze 2 pence coin (97% copper, 2.5% zinc, 0.5% tin) which were made until September 1992 which pre dates the later steel copper coated ones. This is still the nearest size I can find to the US dime. I tried the same air test with this coin and can only get to show at just slightly less than 3". I also noticed whilst i was twiddling with the tuning knobs on the control box and coil, that if you left it running with a tone, when the coin was passed by the coil (air test) it went silent when the coin past the centre of the coil out to 8" but if I placed the coin on the floor it wouldn't read it atall. Ground test ongoing.