SurfMaster Performance

[WesP]

I have finally finished with the tuning of my Surf Master and wanted opinions on how it's doing. I have also included some o-scope pic. My coil is 7.5 inches (190 MM) OD. Made with 30 stranded Teflon wire. 27 turns 372.8 pF 5.5 Ohms. Made with poly spiral wrap and 3m copper mesh shielding.
Air Testing:
Aluminum soda can 15 inches (38 cm)
1 Euro coin 7 inches (17 cm)
1 us penny 5.5 inches (14cm)

[hobbes_lives]

It sounds to me like your detection distance is short for all of those targets. It my be partially due to the coil diameter. I'm used to working with 9" to 11" coils on the unit, but I don't think that's the whole answer.

[dfbowers]

I have finally finished with the tuning of my Surf Master and wanted opinions on how it's doing. I have also included some o-scope pic. My coil is 7.5 inches (190 MM) OD. Made with 30 stranded Teflon wire. 27 turns 372.8 pF 5.5 Ohms. Made with poly spiral wrap and 3m copper mesh shielding.
Air Testing:
Aluminum soda can 15 inches (38 cm)
1 Euro coin 7 inches (17 cm)
1 us penny 5.5 inches (14cm)

Probably good for a 7.5" coil. Detection range for a 1 Euro on mine is about 30 cm for my 280uH 10" coil.

With my 240uH, 9" coil, it drops to about 25 cm, so big difference!

[bernte_one]

wrong IC´s like me

Hello WesP,

please post the ics you have build in.

I think it`s the problem like the one that i have with my surf pi.

http://www.geotech1.com/forums/showthread.php?t=17121

i have similar bad performance

maybe it come from the Latchup effect ???

http://www.elektronik-kompendium.de/...rer/anasw2.htm

translate by youself

if i used the HCF4093BE instead of HEF4093BP the range falls from 15-18cm for 2Euro to 5-10cm could be this problems are too with other ics i have build in?

i post a peformance video if mine at youtube
For coil information click on "weitere informationen" further informaton at video

http://www.youtube.com/user/BernteOn.../0/yUqz6Y1sI_w

@ dfbowers
can post or link some pictures of your coils with datas

i tried several coils from 13cm till 30cm with differnt inductance etc but i can#t reach such range like you
mybe your coils a totally different or my board is build wrong from me
http://fotoalbum.web.de/gast/bernd.marten2/Surf_Pi

thx

[dfbowers]

Hello WesP,

please post the ics you have build in.

I think it`s the problem like the one that i have with my surf pi.

http://www.geotech1.com/forums/showthread.php?t=17121

i have similar bad performance

maybe it come from the Latchup effect ???

http://www.elektronik-kompendium.de/...rer/anasw2.htm

translate by youself

if i used the HCF4093BE instead of HEF4093BP the range falls from 15-18cm for 2Euro to 5-10cm could be this problems are too with other ics i have build in?

i post a peformance video if mine at youtube
For coil information click on "weitere informationen" further informaton at video

http://www.youtube.com/user/BernteOn.../0/yUqz6Y1sI_w

@ dfbowers
can post or link some pictures of your coils with datas

i tried several coils from 13cm till 30cm with differnt inductance etc but i can#t reach such range like you
mybe your coils a totally different or my board is build wrong from me
http://fotoalbum.web.de/gast/bernd.marten2/Surf_Pi

thx

My coil is 22 Gauge solid copper enameled wire (I think) from Radio Shack. It measures .025" (.64mm). It's the standard "magenet" wire that Radio shack sells in a 3 pack of assorted gauges.

I wind 19 turns on a 10" I.D. form. I like to use conduct mylar for sheilding.

Coil measures about 280 uH, 2.4 ohms. I have it set up for a 20us delay using the standard "kit" supplied by Silverdog.

Cable is RG-58 but a USB-2 cable seems to work just as well.

Hope this helps.

Don

[bernte_one]

many thanks very good nice pictures

i will try this settings and cable characteristics

[dfbowers]

many thanks very good nice pictures

i will try this settings and cable characteristics

Question about the pictures at the link below:

http://fotoalbum.web.de/gast/bernd.marten2/Surf_Pi

Are you using 9v or 12v for power?

[bernte_one]

i used 9 volt power batterie but fully loaded it has 10,8 volt is it better to use 12 v ?

[kuraja]

Have you tried shielding the coil?

And...mind you the floor could be with steel concrete, so I'd advise you not to test it anywhere near the: floors, walls, electrical appliances...etc.
12 volts is required for Surfmaster PI top performance!!!

[dfbowers]

i used 9 volt power batterie but fully loaded it has 10,8 volt is it better to use 12 v ?

The regulator has about a 1.5v headspace so it should basically work but you won't get the same current delivered through the coil and audio section. 9V batteries have a high internal resistance. If you are troubleshooting a detection distance problem, that would be the first thing that I would change.

[bernte_one]

thanks for your tips. i will shield coil with the alu tape from my video - adhesive aluminium isolation tape. i make a ring around the coil an leaving a gap to not short cicuit it. and i will use a battery pack of ten enelop batteries 12-13v

[TH Jim]

I cant agree more with Don - when my batteries drain down to 9V my surf PI runs like crap. It was designed for 12V, it should be run on 12V ! By the way Don I have now figured out the offset issues, used Winscope to view the transmit / recieve pulses and made set the offest so there was no clipping. SurfPI runs sweet now, small thin gold ring at 6 inches!

Cheers all

[ossamaussama]

I have finally finished with the tuning of my Surf Master and wanted opinions on how it's doing. I have also included some o-scope pic. My coil is 7.5 inches (190 MM) OD. Made with 30 stranded Teflon wire. 27 turns 372.8 pF 5.5 Ohms. Made with poly spiral wrap and 3m copper mesh shielding.
Air Testing:
Aluminum soda can 15 inches (38 cm)
1 Euro coin 7 inches (17 cm)
1 us penny 5.5 inches (14cm)

dont use sheild and play with dumping resistor

[bernte_one]

i've improved my performance

Hello,

i have changed my HEF4093BP against a MC14093B(E) and used a Batterie holder for 10 AA batteries (12V+). I now i have reached between 20cm and 23cm for a 1 euro coin with a 23cm diameter 18 windings of 0,5mm lackered copper wire coil. I suspect i'm on the right way.

here is the video before i do the tuning (on video i used 9Volt batterie and HEF4093BP)
http://www.youtube.com/watch?v=yUqz6Y1sI_w

Click on more information to get coil characteristics

[bklein]

My real-deal surfmaster needs the Tuner control to be adjusted so that you hear a background "motorboating" tone for most sensitivity. The manual calls it a "click".
I'm curious where this repetitivity really comes from, but I don't hear that in your video.
Do you use 10 cells? Are they Alkaline? New ones would put you then over 15V but maybe the internal resistance drops that down?

Barry