Warning: Creating default object from empty value in /homepages/11/d132647312/htdocs/Amfone/mkportal/include/SMF/smf_out.php on line 47
Eico 730 Modulator




 
The AM Forum
November 30, 2021, 05:00:20 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
  Print  
Author Topic: Eico 730 Modulator  (Read 435 times)
0 Members and 1 Guest are viewing this topic.
k5ygc
Member

Offline Offline

Posts: 62


« on: November 03, 2021, 06:31:10 AM »

Has anyone found a replacement OPT for the modulator? Or would it be best to have it rewound? Thanks Mark K5YGC       Email is kc5ygc1@gmail.com
Logged
W3GMS
Contributing
Member
*
Offline Offline

Posts: 3014



« Reply #1 on: November 03, 2021, 10:09:30 AM »

You may want to consider a modulation transformer from a Johnson Ranger.  Another choice, but not sure if it would fit in would be an ART-13 mod transformer, but based on what you modulating, make sure the turns radio is good. 

Joe-W3GMS
Logged

Simplicity is the Elegance of Design---W3GMS
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1573


« Reply #2 on: November 03, 2021, 04:34:42 PM »

Has anyone found a replacement OPT for the modulator? Or would it be best to have it rewound? Thanks Mark K5YGC       Email is kc5ygc1@gmail.com

If we are discussing plate modulation the modulation or OutPut transformer should require this:

The Impedance ratio is ~ 2.2:1 (Primary to secondary), so the turns ratio should be ~ 1.5:1, (Primary to secondary).

Phil - AC0OB
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
K9MB
Member

Offline Offline

Posts: 31


« Reply #3 on: November 03, 2021, 06:44:54 PM »

A Stancor A3893 might work. Here is the data on footprint.
If it will fit on the chassis, it is rated at 60 watts, so will easily handle the pair of EL34s.

I may have a used one.

If you want me to check, please email me. Good at qrz


* 7EA6A241-190B-43CF-9342-4EF316F51D4E.jpeg (492.72 KB, 2267x821 - viewed 52 times.)
Logged
Pages: [1]   Go Up
  Print  
 
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 0.05 seconds with 18 queries.