The AM Forum
May 28, 2024, 04:36:46 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
« previous next »
  Print  
Author Topic: Best use for this coil?  (Read 3724 times)
0 Members and 1 Guest are viewing this topic.
N0WEK
Contributing
Member
*
Offline Offline

Posts: 782
« on: February 06, 2010, 01:45:36 PM »
I couldn't pass this one up on Epay...



35 turns, 5" dia., 5 1/2 " long winding, 14 taps. It calculates out to about 97 micro H which seems a little big for a Pi output. Maybe a tuner?

Does anyone know what this came out of?

Thanks,

Greg
Logged
Diesel boats and tube gear forever!
w3jn
Johnny Novice
Administrator
Member

Offline Offline

Posts: 4611
« Reply #1 on: February 06, 2010, 02:06:37 PM »
Appears to be the plate tank coil from a BC-669/Hallicrafters HT-14.  That thing covered 1.5-5 MHz or so, and as I recall it's a pair of 807s mudulated by a quad of 6L6s.
Logged
FCC:  "The record is devoid of a demonstrated nexus between Morse code proficiency and on-the-air conduct."
KA8WTK
Contributing
Member
*
Offline Offline

Posts: 872
« Reply #2 on: February 06, 2010, 02:20:22 PM »
Don't think it is out of a BC-669, at least it looks nothing like the one in my BC-669B unit.
That said, pi unit or antenna tuner would be a good use for the coil. Looks like it is set up with a rotary switch to change taps. Nice find.

Bill
Logged
Bill KA8WTK
w3jn
Johnny Novice
Administrator
Member

Offline Offline

Posts: 4611
« Reply #3 on: February 06, 2010, 04:03:15 PM »
You're right, Bill, looking at a pic of a BC-669 the coil has sliders going vertically for each tap.
Logged
FCC:  "The record is devoid of a demonstrated nexus between Morse code proficiency and on-the-air conduct."
W3GMS
Contributing
Member
*
Offline Offline

Posts: 3043
« Reply #4 on: February 06, 2010, 09:45:24 PM »
Looks like plenty of inductance for 160M.  Very nice coil.
Joe, W3GMS
Logged
Simplicity is the Elegance of Design---W3GMS
K3ZS
Member

Offline Offline

Posts: 1036
« Reply #5 on: February 07, 2010, 01:24:11 PM »
I have a coil that looks just like yours, without the switch and connecting wires.   I think it was made by B & W for use as the final Pi-net coil for bandswitching transmitters.
Logged
W3FJJ
Contributing
Member
*
Offline Offline

Posts: 154
« Reply #6 on: February 07, 2010, 01:54:53 PM »
Quote from: N0WEK on February 06, 2010, 01:45:36 PM

35 turns, 5" dia., 5 1/2 " long winding, 14 taps. It calculates out to about 97 micro H which seems a little big for a Pi output. Maybe a tuner?



Is that coil really 5" in diameter? From pic, it don't look like it and I suspect it would have
half the inductance...

Yeah looks like nice pi output coil... 160-10M
Logged
N0WEK
Contributing
Member
*
Offline Offline

Posts: 782
« Reply #7 on: February 07, 2010, 02:31:09 PM »
Quote from: W3FJJ on February 07, 2010, 01:54:53 PM
Quote from: N0WEK on February 06, 2010, 01:45:36 PM

35 turns, 5" dia., 5 1/2 " long winding, 14 taps. It calculates out to about 97 micro H which seems a little big for a Pi output. Maybe a tuner?



Is that coil really 5" in diameter? From pic, it don't look like it and I suspect it would have
half the inductance...

Yeah looks like nice pi output coil... 160-10M


I remeasured it and it's really 5" dia and actually 5 3/4" long in the winding, making it 95 micro H.

Luna is a big cat!  Grin

The calculations I've seen call for about 60 micro H, even for 160 meters.
Logged
Diesel boats and tube gear forever!
Pages: [1]   Go Up
  Print  
The AM Forum  > THE AM BULLETIN BOARD > Technical Forum > Topic: Best use for this coil?
 « previous next »
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone © 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.053 seconds with 17 queries.