Can I use the F19 DD coil on the new F75SE ver2

[Kevin B.]

I was wondering if I could use the 5x10 dd coil that came stock on my F-19 on a new F75SE (ver 2) if/when I buy a new F75. Does anyone think that it would so internal damage to the F75 if I even tried? And if this idea is NOT wise......do they actually make a 5x10 DD coil specifically for the F75SE? It would seem to be a very nice .......marriage? if that coil was used on the F75SE. The 5x10 coil is remarkable for it's tight foot-print. I need a bit more depth than the F-19 is giving me. All of my relic sites are being pounded to death by everybody and I must use technology (and knowledge) to be able to put at least one bullet in my pocket after three of four hour of hunting. '
I was waiting for the new units from Turkey but it seems as if they will not arrive during the best detecting time of the year....for this area.
By the way, I LOVE my F-19 and have kept that unit longer than I have kept most others (I kept a G2 the longest) but the F-19 seems to have a slight depth edge on the G2. I presently use an 11 inch coil on my F19 and it is NO slouch for depth. But....I am on the lookout for an inch or two or extra depth.

 

[foreign object]

cant do it.They are two different freq.machines/coils.

 

[Charlie P. (NY)]

Makes you wonder how they make coils for multi-frequency machines like the CZ-70. Or the 28 frequency Minelab Etrac!

http://www.fisherlab.com/hobby/detector-searchcoils.htm

There is a Fisher coil compatibility chart on the bottom of the attached page off the Fisher website.

If you go to the above link you can see some models use the same model number of coils. But the F-19 does not intersect the F-75 for any coil.

 

[ez4sure]

http://www.findmall.com/read.php?80,1332879

 

[Bill_S]

I use the F75 small football coil on my F19 and it seems to do ok. I also use the F70 10" concentric on it. I do believe the F19 coil would work but may not give the best results.

 

[detectingMO]

No damage but you'll lose the last 2" inches of fringe detection depth. Which could be argued as a good thing coming from F19 to F75 because the ID is so jumpy those last couple inches anyway. It will feel "clipped" going from great solid detection to nada almost instantly. ID is still nearly identical.

 

[TabWhisperer]

Makes you wonder how they make coils for multi-frequency machines like the CZ-70. Or the 28 frequency Minelab Etrac!

I'll take a stab at this. Mind you I am reflecting back to high school electronics from 40 years ago. I think what you will find is that multi-frequency detectors use a base frequency and then use multiples or harmonics of that base frequency that is first generated. The V3i uses 2.5kHz, 7.5kHz and 22.5kHz. The usable multiples of that are 5, 7.5, 10, 12.5, etc. For this case 7.5kHz is three times the 2.5kHz and 22.5kHz is 9 times 2.5kHz. The CZ3d uses 5kHz and 15kHz or 5kHz times 3 for the higher frequency. The CTX starts at 1.5kHz and has many multiples. In the case of the Fisher F19 and F75 you are looking at 19kHz versus 13kHz operating frequencies. If the F19 were to be a multi-frequency detector and had 13kHz as it's base frequency the first multiple would be 26kHz. The F19 and F75 simply aren't multiples of each other. The second part of the bigger problem is the coil. The coils are basically antennas. Antennas are normally optimized by length of the wires to match the wavelength of the frequency or some other length by 1/2 of the wavelength for instance. Plus there is other magic stuff that goes into making them work right. But the pattern you will see if coils that work with different model of detectors generally have common base frequencies so the coils (antennas) are tuned properly for them. Sure in some cases you could plug a coil on a 13kHz machine that is designed for a 19kHz machine and radio waves will be transmitted and received. But the performance will predictably be pretty poor compared to a proper coil. There are a lot of issues they probably have to think about like power consumption, which metals react best to certain frequency ranges, etc.

I think there are some good documents for reading about basic detector design but I don't have them right now. I know Mr Johnson used to have some good stuff on the Fisher site.

 

[Tom Slick]

I have both the F75LTD2 and the F19. I swap coils on them sometimes but I almost have the same coils for each. In testing I have found that both detectors will lose about an inch in depth using a coil made for the other. My F75 has the 11"DD, 5"DD , and the 3"x6" concentric. My F19 has the 11"DD, 5"x10"DD, 5"DD, and a Nel Hunter 8.5" x 12.5". I sometimes use the 3"x6" F75 coil on the F19 in trashy areas where depth is not an issue as the concentric coil works better at discriminating bottle caps, and pinpoints small targets better than the 5"DD.