Good News about the Mark 1

[kasparov747]

new mods for the mark 1

hopefully someone will put out a few new circuit mods for the mark 1 now that the schematic is around. maybe a different depth mod other than the resistor change. this should renew interest in modding the mark 1. thanks again reg.

[Altra]

Thanks to Mr. Payne and Reg!

These may be the patents with schematics that cover the Mark1? If so will help to explain and understand the circuits in the schematic.

-mark

[kt315]

Reg,

thanks to you and George but these PDFs are cramped please give an original file in colour BMP format zipped.

sincerely yours

[petersv]

Yes, thanks for getting these. The MK1 is really a great machine, I bought a new one from Keith Wills at east Texas last year. You can't ask for a simpler to maintain machine. Some of the White's coils will work but by default the Bounty hunter coils work.

If I remember correctly the detector produces 120 tones, the coin select is a notch set up that i would like to see changed to being variable in width. In all metal mode this machine has the best target profiling I have ever used. Once you know how it will tell you 100% if the target is aluminum or not. This is coming in handy for small jewelry hunting and avoiding small bits of foil and pull tabs. It will detect a gold clasp @ about 3-4" in air and 2.5-3.5" in the wilds, depending on its diameter. If the frequency could be doubled to 14 or 15 khz I believe it runs at 7 khz, its affinity for gold could no doubt be improved. As it sits, i have never done better with any other detector for jewelry count while coin hunting.

As a coin hunter I don't think it has a peer, except for maybe the original Bandido 2. At its lowest sensitivity it will easily draw out dimes at 6-8". What was most surprising is that it does not discriminate against Canadian coins . It finds them as easily as US clad. It loves our 1 and 2 dollar coins, many newer machines treat these coins as trash.

Metaldetectorreviews calls it a "cult" detector.....cool!

I an ideal world the package would be redesigned so that the guts would be worn around your waist and the shaft would only have the meter, AM/DISC/RETUNE toggle, the main disc knob and of course the coil head. The rest of the knobs could easily be left on the hip mounted box. If the pcb could be redesigned for surface mount.....sorry I will just stop dreaming right here.

Analogue machines rule, the quality of the audio on this unit is second to none. It chirps and groans and sings songs. One user that I know who has used one since it was first introduced says that there is a special sound/song he has come to know that spells gold everytime.

I look forward to the insights of the many very talented electronic gurus here. It maybe fun to make a OO coil for this machine?

take care.

[WM6]

Hi Petersv

thank you for your interesting report.

I cannot only imagine myself what use of 120 tone is? It is hard to diferentiate between 12 tone, let alone between 120.

[petersv]

120 tones

You would think that, I did also. Here is an experiment.

Go through your day and pay attention to how often you respond to ambient sounds while you are going about your business. We have developed so that our ears do so much back burner processing of information that we can go about our business and not have to pay conscious attention to it. When something important happens it gets our attention and we deal with it. This does not seem to be quite as strongly the case with our eyes, other than with peripheral vision.

I personally found that detectors that rely heavily on video information slow down my hunting quite a bit I spend too much time watching the screen while swinging and when a signal comes through I am looking for too exact/repeatable/stable a reading. I also end up with a sore neck.

With the rich audio output, I just toddle along and end up listening for sound bites. You are not listening for a specific tone, usually, but a series of tones. You can usually remember fairly substantial pieces of a song that you have heard for the first time much better than a string of numbers. You are much more able to sort through a song than a barrage of numbers our brains seem to have dedicated a substantial amount of horsepower to this type of information analysis and memorizing. For me this extends to the type of visual output device. An analogue needle tells me a lot more than a bunch of scrolling numbers. How the needle bounces or in what range it spends most of its time is easy to interpret.

The next extension is digital versus analogue.

Just my two cents worth.

[Melbeta]

The Mark 1 is a very good stable detector....

The Mark 1 (gray plastic body machine) is a very good stable detector. Then around Christmas time, they came out with the same machine, but in a red plastic case, called Mark 1 LTD. I think it was slightly better, but there may have been just a minor difference in color case, and there was no difference in the actual electronics.

Reg, I used to read your detector magazine articles, if you are the same person I think you are. I am in Colo Spgs, and was a dealer for Teknetics, Whites, Compass, Garrett, Gold Mountain, AH Pro, and a few more. If you ever get down this way, look me up and we will talk. I am a Colorado historian and have a fantastic collection of Colorado material.

The last time I spoke with George Payne, he was at Compass, and I asked him how I could soup up my Mark 1, and he replied "I believe it is just one part that you change, and I will look for my schematics and get back to you". Well, right after that, Compass went out of business, and George never got back with me. I would really like to know what that "one part" is, and I will change it myself.

[Reg]

Hi Melbeta,

Yep, I am that same guy. I just live down the road a ways from you.

George told me basically the same thing that it didn't take much to add some depth to the Mark. He mentioned he was conservative in the design so it would be such a nice quiet detector.

My last email conversation with him indicated he would look at the Mark 1 schematic when time permitted, but I also got the impression he had a lot of other things that came first.

I will send him another email and let him know we would appreciate what he can remember about increasing the sensitivity of the Mark 1.

Reg

[Melbeta]

Thanks Reg S

Hi Melbeta,

Yep, I am that same guy. I just live down the road a ways from you.

George told me basically the same thing that it didn't take much to add some depth to the Mark. He mentioned he was conservative in the design so it would be such a nice quiet detector.

My last email conversation with him indicated he would look at the Mark 1 schematic when time permitted, but I also got the impression he had a lot of other things that came first.

I will send him another email and let him know we would appreciate what he can remember about increasing the sensitivity of the Mark 1.

Reg

I appreciate it. I am a lover of the Compass and Teknetics machines, and of course, the older good machines. I also write, did some booklets and self published mine with an offset press and a Standard binder. I still do some booklets, although smaller amount now, just for self satisfaction and for those who want copies of out of print stuff. You come up here sometime, lets get together and have coffee. I enjoy history.

[duggr]

Any more info

on the Mark-1 Depth Mod?

[turtlebowl]

Clarification on the Mark Series Schematic_ Here

The following circuit drawings were created to clarify the "blurry" and missing portions of the Tektronics Mark Series Schematic found earlier in this thread. The drawing covers both the Mark I and Mark III. I traced and varified each portion using my Mark III Detector. It is very interesting to note that apparently the difference in the Mark I and Mark III are not a simple elimination of a few controls. The fixed resistors in the sensitivity circuit are also different as well as a few others. These are in addition to those resistors listed in the Original "Chart A". My "Chart A" lists these additional resistor differences as well. See below. Many Mark users have stated that they thought the Mark III was more sensitive than the Mark I. Waiting for more input from users on that topic.
Also interesting is the AGB circuit shown on the drawing that was never put into production becuase of the added cost at that time. See the link below for georges own words on this AGB design that almost made it onto the Mark Detectors.

http://jb-ms.com/Baron/gb.htm

[turtlebowl]

Georges statement on his AGB Circuit Mark Series

I mis-quoted George Payne on his comments regarding the AGB circuit he designed for the Mark Series. Actually what I did was not give the whole quote. I stated that George said he was very pleased with the design and its initial performance. What I neglected to say was that he continued and said it needed alittle more developement becuase it could lock on to large targets. Matbe that was part of the reason he left it off the production model. Still very interesting reading though....see his artical link in my previous post if your interested in reading the entire artical on Ground balance circuits.

[Merc]

Has anyone cleaned up the original Mark I drawing? I thought about trying to make it more readable like I did the Big Bud Pro schematic but I would rather not if someone has already done it.

Merc

[Merc]

Mark I schematic Cleaned

I've been working for some time to clean up the Mark I schematic. The forum won't allow me to upload a
PDF over 2MB so I have had to scale it down quite a bit to get below that limit. I hope it's still more
readable than the original.

Enjoy,
Merc