[AMRadio] 4-400 first made when?

cemilton at aol.com cemilton at aol.com
Fri Mar 23 16:09:33 EST 2007

Brad and the group,

My posting said 20J................no such animal to my knowledge.  My 
age is allowing the thoughts of the 20V2 and the 300J to run together.  
I should have said, "the transmitter was a Collins 300J and the upgrade 
made it a 20V-2."  Now I feel better.  I'm reasonably sure we changed 
some iron but thats been a long time ago.  We did add a Rube Goldberg 
designed homebrew solenoid arrangement that allowed use of the power 
cutback switch.  The station ran 1kw day, and .25kw night.  The 
transmitter was remotely controlled and if I remember correctly, the 
R/C unit was made by RUST, Corp..  I'd suggest getting a schematic of 
the 20V-2 and comparing it with the 300J to make your restoration a bit 

Funny, I can still remember the Ep , Ip and I (ant) plus the antenna 
resistance.  1500v, .225a, .73a and 470 ohms. (.25kw readings)
For the 1kw power setting they were  3100v, .455ma, 1.49a and 470 ohms. 
  I must have read those meters hundreds of times.  We were always wary 
of an FCC visit.  And we had one or two while I was CE.

Those were the days.  Brad, if you were close by I'd volunteer to 
assist in bringing the old transmitter back to life.  They were 
excellent pieces of gear.

Gud luck es 73


-----Original Message-----
From: uvc1 at verizon.net
To: amradio at mailman.qth.net
Sent: Fri, 23 Mar 2007 1:44 PM
Subject: RE: [AMRadio] 4-400 first made when?

I've not researched the 4-400, but I can say for sure we replaced the
4-125's with 4-400's when we upgraded our broadcast transmitter from
.25kw to 1kw around 1961.  The transmitter was a Collins, 20J and the
upgrade made it a 20V-2.

73 de W4MIL

Chuck, and the rest of the group,
I have a Collins 300 J basket case (no iron) I am changing it to a 
20V2, any
advice on the 4- 400 swap, does anyone have any of the transformers, 
not have to be out of a Collins 20v2, just needs to be for 4-400's)

No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.446 / Virus Database: 268.18.17/730 - Release Date: 
7:44 AM

AMRadio mailing list
List Rules (must read!): http://w5ami.net/amradiofaq.html
List Home: http://mailman.qth.net/mailman/listinfo/amradio
Partner Website: http://www.amfone.net
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:AMRadio at mailman.qth.net
To unsubscribe, send an email to amradio-request at mailman.qth.net with
the word unsubscribe in the message body.

AOL now offers free email to everyone.  Find out more about what's free 
from AOL at AOL.com.

More information about the AMRadio mailing list

This page last updated 19 Feb 2018.