Warning: Creating default object from empty value in /homepages/11/d132647312/htdocs/Amfone/mkportal/include/SMF/smf_out.php on line 47
Need advice on RF choke replacement




 
The AM Forum
April 11, 2021, 11:51:22 PM *
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: Need advice on RF choke replacement  (Read 1164 times)
0 Members and 1 Guest are viewing this topic.
WO4K
Contributing
Member
*
Offline Offline

Posts: 110



« on: August 14, 2016, 08:35:44 AM »

Application: DX-100B final amp, RF choke and parasitic chokes for the 6146 tubes.
Symptom: Transmitter output is low (70 watts on AM when I normally get 125). Plate reads a max of 75 milliamps on the meter (spec calls for 150 ma). Grid and voltage readings are good (400v).
Observation: Replaced both 6146 tubes (both tested marginal under load) and noticed the parasitic choke resistors are burned and test bad on the VOM, RF choke appears toasty, too.

So I want to replace the RF choke (part # 45-4 in the manual) and parasitic chokes for the 6146 tubes in the final. Thought I was going to have to home-brew my own parasitic chokes, but found the exact replacement parasitic chokes at Surplus Sales of Nebraska. They also have an RF choke that I may be able to use, but I just need to check with you guys to be sure. The manual calls for 1 mh at 500 ma. The one available at SSN is 1.1 mh at 1 amp. So it is within + - 10% on the inductance. Good to go. But the amperage of the the SSN choke is double that of the 500 ma spec in the manual. I want to be sure the amperage factor is not critical. I suspect it is similar to the wattage in resistors or voltage in capacitors: More is OK, less is not OK. Advice, please.
Logged

Patrolling the ionosphere from Dunedin, Florida.
W7TFO
WTF-OVER in 7 land Dennis
Contributing
Member
*
Offline Offline

Posts: 2319


IN A TRIODE NO ONE CAN HEAR YOU SCREEN


WWW
« Reply #1 on: August 14, 2016, 06:28:23 PM »

One Amp is a lot more reliable than the original.

73DG
Logged

Just pacing the Farady cage...
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 0.047 seconds with 18 queries.