View Single Post
  #22  
Old 08-09-2009, 01:38 PM
Max's Avatar
Max Max is offline
Guru
 
Join Date: Jan 2007
Location: Mars (cool)
Posts: 2,684
Default

Quote:
Originally Posted by rajesh View Post
hi max i also buit a t/r locator 2048 hz. transmeter working well. but i have problem in receiver coil in L/C network. there are coil size too big for testing purpose [12 inch diameter ] 26 awg - 15mh inductance. can you recmond me a small coil /capecitor for 2048 frequency.......... you knowe that this device is working in russian side. gary lecomte modified this
Hi,
I don't know about this specific design...

but if need a good coil for 2048Hz range and capacitor for it I suggest this one:

wind on 300mm former 51turns of 30AWG wire (0.25mm bare wire, 0.28with varnish); coil must be tight and rigid.

Use 3u3 poly cap with it...

Then run a small coil (explorative coil, say 100turns on 2.5cm diameter) with a frequency generator at 2048Hz, try to get maximum output voltage from resonant tank, can use ac voltmeter or scope for that.

If have to lower frequency add 1 or more turns to coil, otherwise less turn.

If need e.g. 20cm coil can try this:
use 67turns as start, 200mm former, 30awg wire , cap always 3u3 poly.

Change turns as described, tune for max output voltage at 2048Hz.

To get exactly 2048Hz can use a 32768hz xtal oscillator (cmos gates one is ok) , then divide by 16 using a ripple counter like 4024, input at pin1 and output at pin6 ...div by 16).
Then can drive a transistor with small coil (explorative) as load.


Kind regards,
Max
__________________

"Kill for gain or shoot to maim...
But we dont need a reason
"

someone said...
Reply With Quote