Red Baron coil parameters

[Math]

Hi, I have a Bounty Hunter Red Baron VLF SPD.. control box only
I think this is the RB7 model circa 1979? but im struggling to find a coil for it

Anyone here ever built one of these coils or has the coil parameters for it?
and does anyone know what frequency they operate at?

Thanks

[kt315]

hi
hard to answer if i am not in BH production and not at territory of USA.
it was era of symmetrical coils... we have just data on '100, 200, 300 series coil' and a schematic of RB7.
i think frequency is 6.6 traditionally for BH. Melbeta has to correct me.

pleasure

[Math]

Hi Kt315 thats great thanks.. ill look those up here
Were they concentric coils in that era?
Id like to make a DD coil for it i think

[Carl-NC]

Yes, 6.6kHz. Original coils were "omega" style. I believe both the TX & RX were CT, and there are add'l components in the coil. There is a pic of the inside of one in ITMD. I expect this would be an exceptionally hard coil to make. I see lots of old RBs selling on eBay for cheap, that's the way I'd go.

[kt315]

the forum has this schematic of DB7 and pic of 100-200-300 coil that not fitted DB7 but will be useful.

pleasure

[Qiaozhi]

Plus pages 2 & 3.

[Math]

Hi Carl thats great thanks.. i thought id seen an RB coil layout somewhere before
I had looked in ITMD at the IB coils section after the Raptor project for it but i see
its in the earlier Induction and Coils section page 56 (2nd Edition) showing the circuit board inside the coil with tuning components.. i agree it looks a bit too complicated!
I will keep my eye out on Ebay.. theres a green IB 1/2/300 series coil on there at the mo.. its an 8" DD as in the coil wiring jpg posted above..
Thanks KT and Qiaozhi for those files.


Ive started looking at the first board.. shown on "D-rb7 page1aa" and noticed the schematic is missing some parts around those demod chips so ill update it and post here when im done.. im thinking of trying that IB series coil.. its 4pin not sure it has any coil shielding though.. a better bet maybe to build a DD myself and see if i can get a simpler design coil arrangement to work on the Red Baron.. i might experiment upping the frequency to 11-13khz aswell to increase sensitivity to low conductors.
I have a Fisher 1265X i took up to 16khz.. big project, lots of changes and time to
do but it works well and ive learned a lot in doing it.. i think this Red Baron is next!


Thanks

[Carl-NC]

I'm fairly certain the IB-series coil won't work on the RB7.

[kt315]

yes, Carl did good work but some 'tiny elements' were not viewed. https://www.geotech1.com/pages/metdet/info/coils.pdf
there are always a part 'know-how' in a shadow.