Dads Fisher VLF-552D...excellent condition...kinda

[petewp]

Never been dropped, or abused or water damaged or bent or whatever. It turns on but I dont know what the 6 buttons do. The discriminator button goes all the heck they way around and keeps on going around and around. Is this normal?

Everything else seems intact. I just dont know how the heck to use it. Totally new here - but i hsave found a circa 1975 Shlitz beer can on the high tide line in 5" sand. I guess it detects metal.

This particular detector was $350 back in 77. So back then anyway - it was expensive.

Can anyone show me to a user manual or atleast walk me thru it if you have the time? And whats the red button that pokes out of the end of the tube at the handle end?

Takes a dozen AA batteries [groan] but I want this baby to see its potential. I just dont know how to find it.

thanks in advance!!

Pete

 

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[U.K. Brian]

Pre motion but a great detector !

Standard coil was 8". Frequency 4.5 kHz. Battery life 60 hours with good batteries.

Controls were GNC (ground neutralizing circuit) phase adjustment control.
GNC sensitivity control.
Discriminate level.
Discriminate sensitivity adjustment.

The discriminate phase level allows you to control the rejection level independantly from the ground neutralizing control.

Other control must be the on/off volume adjustment. Think that leaves use one short. Trouble is I can't remember what that would be as I had the 553D which had loads of other adjustments like frequency modification, ten turn tuning control etc. Hang on must be threshold.

The red push button is what you use to set the tuning. Once the detector has been set to give the best performance for a site pressing the button will retune it to the optimum setting. Detectors of the time suffered from tuning drift that doesn't affect modern motion machines.
What you have to remember is that this is well pre motion. You could not eliminate ground minerals and discriminate at the same time. This meant for the best/deepest results you had to detect in all metal (no discrimination) and when a target was located switch into the discrimination mode to I.D. it.

To start off switch on and continue turning the knob (this could be threshold OR volume) can't remember because I haven't seen this model in 30 years. Threshold is set by holding the detector with the coil in the air out in front of you, depressing and holding the red tuning button and then turning the threshold knob until you have a slight audio threshold. At this point release the red button. Every time you press this button it will return you to the tuned position you have just set.
Ground balance in the ground balance mode (switch might be labelled GNC or GB). On a clean bit of ground pump the coil from one inch to nine inches up and down and pay attention to the threshold as the coil approaches the soil. If the sound increases you have to adjust the ground balance control down (should be counter clockwise), if it decreases adjust the control up (clockwise). Raise the coil up, make a slight adjustment and press retune to return threshold to its original setting. Repeat the up down proceedure and adjustment until there's little threshold whether the coil is in a high or low position.
GNC sensitivity if turned up adds depth on good ground but may have to be reduced for bad.

Discrimination sensitivity is the same as the GNC one. Normally you use as high as the soil conditions allow. The discrimination level should be set as low as you can cope with. On old sites just knock out small iron nails. Parks/top of beach increase the level to just knock out foil. When you get use to the detector reduce settings a little further so that the item you want to reject is not completely knocked out but gives a broken tone.

In a park or the top of the beach you can detect in the discriminate mode all the time. Costs depth but adds to speed of searching. If you are on damp/wet sand you have to use the discrim. mode. If you increase discrimination to the point that larger foil starts to drop out this will be near the point that the positive salt effect is eliminated.

No worry re the correct sweep speed with these older machines. Use what suits and with an iffy signal you can just dig a hole coil sized and drop the coil down until you get a better I.D.

Sorry I can't remember more. Just play about with it. Ground balance seems complicated at first but once you do it its little trouble. One worry is the discrimination knob turning freely. It shouldn't do that. Could just be the knob loose on the shaft. It needs sorting though.
Though there doesn't seem to be any test reports on line see if you can find/download the Garrett Groundhog instructions (P.B. not ADS). The settings of these machines are very similar.

Best of luck Brian

 

[Sandman]

Thanks Brian..... I had to read your post to refresh my memory. Ahh then were the days, huh?