I have a 1990s era Fisher Gold Bug, the original 19 kHz analog version, long since replaced by newer models. The old 19 kHz model was not particularly hot, but it did have an ability to ground balance out some hot rocks that newer and hotter VLF machines struggle with.
Original Fisher Gold Bug Data & Reviews
The detector came with a 10" elliptical search coil. I have a couple very rare 3.5" round coils that Fisher made for these models before the little 4" x 6" elliptical replaced it. It's the smallest search coil I've ever owned for a commercially sold metal detector, making the unit into more of a probe than a normal detector.
The threshold was cutting out if the detector was bumped, something loose, so it's been sitting idle for a very long time. I decided it was doing no good as is, and by chance had an opportunity to call Felix at Fisher recently. Felix is another old-timer in the industry like myself, who I have not talked to since I left my old dealership in Alaska over eight years ago. Anyway, since the detector is still actually functional Felix figured they could give it a good refurbish and fix whatever is loose.
The main thing I wanted, however, was to get the detector tuned for the 3.5" coil. Most people do not know it, but analog Gold Bugs are hand tuned for every coil. The coil they ship with is tuned for the detector, or should I say the detector is tuned for the coil. Accessory coils may or may not be a perfect match if the original coil is swapped out for something else. Long story short is I am asking them to match the detector to the 3.5" coil as well as is possible.
The original Gold Bug is a genuine classic. Prior to it, detectors were large square boxes with extremely poor ergonomics. The Bug features a very compact control box that is removeable from a S rod, enabling easy chest or hip mounting. The design seems normal now, but you have to have used what came before to see the genius of what Fisher did with the Gold Bug. 19 kHz was also a radically high frequency at the time, as people were just catching on to the idea that higher frequencies are better for small gold nuggets than the lower frequencies that were the norm of the time. The 19 kHz Gold Bug replaced the 4.5 kHz VLF-660 Mother Lode as Fishers top nugget detector. Frankly, Fisher was not seriously in the game prior to this point, with Garrett probably the leader in VLF gold detectors at the time. A new company named Minelab was just starting to sell detectors in Australia, and had yet to really make a name for themselves.
Anyway, control box and coil boxed up and on the way to El Paso. I'll let you all know how long it takes and what the result is.
Here is a picture of one of the coils. The Gold Bug coils first used a gray dual lead cable, which was replaced very early on with the stouter black cable used to this day. This is the older coil of the two, though it also has less wear. The one I sent in has the heavier cable but is in poor condition. I need to reinforce the coil ears when I get it back since one is cracking. But I decided I wanted to use the coil with the heavier cable, with this older one serving as backup until I sort this all out. And in case anyone is wondering, the old 19 kHz coils do not work on the newer digital versions of the 19 kHz Gold Bug.
3.5" round search coil for original analog Gold Bug
To reiterate what a radical design advance the Gold Bug was at the time, here is a picture of the detector it replaced, the 4.5 kHz Mother Lode...
Fisher VLF-660 Mother Lode metal detector
And the new 19 kHz Gold Bug...