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Mike Toon
Joined: 01 Jan 1970
Posts: 4664
Location: Burbank CA
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| Posted: Dec Thu 13, 2007 2:34 am |
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I got Norms schematic today so I thought I'd post it.
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35Z5
Joined: 01 Jan 1970
Posts: 6630
Location: Chesapeake VA
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| Posted: Dec Fri 14, 2007 2:56 am |
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Hi Norm
What size coil form do you recommend???
I have 100/25 turn coils I wound for a 6BM8 xmitter, I'll prob start by removing 23 turns...  I hate windin'... Also have a 12K5, ought to be a "piece O cake" to build... Me getting it to operate, now that's a different story...
Tom |
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Norm Leal
Moderator
Joined: 01 Jan 1970
Posts: 23858
Location: Livermore, CA
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| Posted: Dec Fri 14, 2007 4:04 am |
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Hi Tom
Any coil made for the broadcast band will work. Just add a couple turns for the tickler. I wouldn't remove your 25 turn coil. You might want to use it for antenna and ground input?
Won't have a problem if you are familar with regen radios. If not familar will take a few minutes tuning.
Suggest using a very low value pot for R1. The type used as speaker fader control in car radios will be ok.
_________________
Norm |
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35Z5
Joined: 01 Jan 1970
Posts: 6630
Location: Chesapeake VA
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| Posted: Dec Fri 14, 2007 4:20 am |
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OK Norm
I've come up with a fairly different form anyway, so I'm going to wind... The 12K5 tests good, I'm on the way...
Hopefully I can make it work, I wanna take pictures... 
Tom |
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Kevin Kuehn
Joined: 01 Jan 1970
Posts: 2039
Location: N.W. Wisconsin
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| Posted: Dec Fri 14, 2007 4:52 am |
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Tom,
Looking forward to pictures.
Norm,
Whats the purpose of the .022 speaker cap in this circuit?
Kevin |
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RCWade
Joined: 14 Jul 2007
Posts: 718
Location: Sun City Az
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| Posted: Dec Fri 14, 2007 5:43 am |
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the .022 ufd cap by-passes the RF sig to ground ( b+) while the audio sig is passed by the transformer to the next stage.
RCW
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A man learns very little if he speaks only to himself |
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ff4312
Joined: 09 Jul 2008
Posts: 199
Location: Florida
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| Posted: Mar Sat 07, 2009 3:22 am |
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A couple questions:
At what voltages should the caps be rated at?
Wattage for the resistor?
Could I use a different coil to receive SW?
Thanks,
-Shane- |
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Rich, W3HWJ
Joined: 30 May 2006
Posts: 1870
Location: Santa Rosa, CA
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| Posted: Mar Sat 07, 2009 9:51 pm |
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| Quote: | A couple questions:
At what voltages should the caps be rated at? |
Since it uses a 12 V supply, 16 V or 25 V caps should be fine.
| Quote: | | Wattage for the resistor? |
The resistor doesn't dissipate any power so a 1/4 W or 1/2W is fine; whatever you have handy.
| Quote: | | Could I use a different coil to receive SW? |
Yes. You would need fewer turns, of course. You might try about 40 turns with a 6 to 6 turn tickler coil. Experiment! That's where the fun comes in!
Rich |
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ff4312
Joined: 09 Jul 2008
Posts: 199
Location: Florida
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| Posted: Mar Sun 08, 2009 8:15 pm |
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| Thanks Rich! |
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Rich, W3HWJ
Joined: 30 May 2006
Posts: 1870
Location: Santa Rosa, CA
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| Posted: Mar Sun 08, 2009 8:21 pm |
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Sorry, I meant to write "6 to 8 " turns for the tickler winding.
Rich |
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grampibear
Joined: 01 Jan 1970
Posts: 795
Location: Brentwood, CA
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| Posted: Mar Mon 09, 2009 1:47 am |
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| I would like to build this radio using a variable tickler instead of the reostat. I am having trouble finding a 12K5 tube though. It seems to be a bit scarce. |
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ff4312
Joined: 09 Jul 2008
Posts: 199
Location: Florida
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| Posted: Mar Mon 09, 2009 2:56 am |
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I got mine off of ebay, Probably paid too much but oh well. There were like 4-5 on there the other day. The one I bought was $10 incl. shipping.
Good luck.
-Shane- |
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35Z5
Joined: 01 Jan 1970
Posts: 6630
Location: Chesapeake VA
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| Posted: Mar Mon 09, 2009 3:23 am |
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Radio Daze and likely the other suppliers have 12K5s for $3...
Tom |
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ff4312
Joined: 09 Jul 2008
Posts: 199
Location: Florida
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| Posted: Mar Mon 09, 2009 3:34 am |
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I went to Tubes And More and they didn't have them so I immediately turned to ebay, Forgot about Radio Daze.....DOH!
On another note I was thinking of making both BC and SW coils complete with their own ticklers for this, and then wiring them in so I can just flip a switch/s depending on which band I want. Based on Rich's earlier post I should be able to do this w/ o mods to the rest of the circuit right?
-Shane- |
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wcirco
Joined: 27 Feb 2009
Posts: 2724
Location: Just Outside Annapolis MD
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| Posted: Mar Sat 21, 2009 2:46 am |
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| Do you wind the tickler around the broadcast coil or above? |
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WA6VVL
Joined: 28 Aug 2007
Posts: 145
Location: Tustin,CA
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| Posted: Mar Sat 21, 2009 3:05 am |
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The tickler/feedback winding can be separated from the main coil by about 1/8" if you're winding it on a standard plug-in coil form. In practice, it can be wound right around the main coil... Although 6-8 turns will suffice, anything in the area of 10-45 turns will work as the setting of the regen control will control the feedback.
Dave - WA6VVL |
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Norm Leal
Moderator
Joined: 01 Jan 1970
Posts: 23858
Location: Livermore, CA
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| Posted: Mar Sat 21, 2009 3:16 am |
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Hi
Like mentioned tickler can be wound close to the tuning coil. With this tube tickler only needs a turn or two. I wrote two turns but found even 1 was enough when I built the circuit.
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Norm |
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35Z5
Joined: 01 Jan 1970
Posts: 6630
Location: Chesapeake VA
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| Posted: Mar Sat 21, 2009 3:32 am |
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Here's a pict of the one I built, you can see the tickler coil waving in the breeze...
Tom |
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ff4312
Joined: 09 Jul 2008
Posts: 199
Location: Florida
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| Posted: Mar Sat 21, 2009 6:46 pm |
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| Could I use the audio transformer from my junk Westinghouse WR-179(5 tube AMer)? It looks the same as the one pictured but I don't know the specs. |
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35Z5
Joined: 01 Jan 1970
Posts: 6630
Location: Chesapeake VA
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| Posted: Mar Sat 21, 2009 7:25 pm |
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That was the 1st transformer I tried from a battery portable, wasn't very happy with it or one from a AA5...
Read through my posts in this thread, where I talk about the transformers I tried...
http://www.antiqueradios.com/f ... p;p=629058
Comments just after the picture and scope waveforms have the most info on transformers...
Tom |
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