C-Scope 1220b

[Peter Jones]

Hi, does anyone know of any useful mods (stability, gain etc) for the classic C-Scope 1220b (the one with the plastic "goose neck") ?

Also, has anyone "modernised" one of these (i.e. "S" or straight stem with an armcup, and a more up-to-date control box), I'm guessing the PCB is not also an odd shape and is able to fin in a normal case ?

(Just waiting for one to arrive in the post)

Thanks in advance,
Peter

[asolone]

Hi, does anyone know of any useful mods (stability, gain etc) for the classic C-Scope 1220b (the one with the plastic "goose neck") ?

Also, has anyone "modernised" one of these (i.e. "S" or straight stem with an armcup, and a more up-to-date control box), I'm guessing the PCB is not also an odd shape and is able to fin in a normal case ?

(Just waiting for one to arrive in the post)

Thanks in advance,
Peter

to obtain the best stability you have to put the sensitivity to a minimum and use the headphones

[mikebg]

Peter, the preamp of 1220 operates with very low gain (about 9 times). For max sensitivity, you should increase the gain of preamp until it starts to saturate in output.

[asolone]

Peter, the preamp of 1220 operates with very low gain (about 9 times). For max sensitivity, you should increase the gain of preamp until it starts to saturate in output.

attention to this metal detector is no motion, the more amplified and more mineralized from the soil is disturbed, it will be difficult to maintain in tune threshold

[Peter Jones]

Thanks to both of you for the replies.

Got it in the post today It's in better condition than I thought. In-air tests are comparable to several motion-type detectors I have had (though somewhat short of the performance of an XLT I used to have)

Perhaps I should have introduced myself in my first post, I've been detecting on and off for many years, starting with non-motion types (viking 6 which used to drift for fun) and have made a couple of my own (with varying success, aren't coils fun?) and used to work in electronics. I also used to frequent this very forum (though my original login details are lost in the mists of time)

The soil I mainly detect is pasture, so most detectors can happily run at max sensitivity (or close) - the preamp gain figure is interesting, might experiment with that (I can always revert to standard if it goes pear shaped). Also possibly the battery system I may change from the current (lol) 12xAA (!)

Ergonomics and possibly coil size/type are worth investigating too but firstly I'll see how well it performs in the field

[asolone]

use c.scope 1220 for research on materials of war 1(1915-1918 italy front),use the sensitivity to a minimum, the audio vco response is very good for research austrian kappenabzeichen, with high sensitivity the audio response is not very good, is disturbed from the ground,increasing the amplitude of the signal in the channel all metals the sound of the vco changes, sounds different.I also did a lot of evidence that suggested by mikebg, it happens that the answer to the materials on the surface saturates and the response signal is no longer linear

[Peter Jones]

Mikebg - Thanks for the tip, I shall investigate further.

I've got coming in the post, an Arado 120 of similar vintage - should be an interesting comparison. (vastly different frequencies)

Asolone, it sounds like you detect on difficult ground ? Sounds like the interesting finds are worth the effort though.