Greetings - Are there modern-day replacements for the Century 21 "MRF 472" PA drivers and the PA pair of "MRF 475"s? I tried with Digikey and Newark, and drew the electronic equivalent of a blank sta
Are these what you're looking for, Woody? https://www.rfparts.com/rftransistors/transistor-mrfsrfm/rftransistors-mrf-400/mrf472.html https://www.rfparts.com/rftransistors/transistor-mrfsrfm/rftransis
Author: Gary J FollettDukes HiFi <dukeshifi@comcast.net>
Date: Sun, 7 Aug 2016 12:13:10 -0500
I have a parts cadaver C21 that has these, if used parts will meet your need. Gary _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.co
Many thanks to Dave Bowker, Mike Pagel and Steve Berg for pointing me in the right direction. My follow-up question is "how important is it that the transisters be matched pairs?" 73, Woody KO3S From
Woody, Since no one else has replied, I'll take a shot at answering your question. The following is from Motorola Application Note AN-593 "BROADBAND LINEAR POWER AMPLIFIERS USING PUSH-PULL TRANSISTOR
Spend the extra money with RF Parts Co. to buy the matched pairs for circuits that use two opposed transistors. If one of the numbers is a single stage driver you only need one. - Stuart K5KVH ______
Just an FYI, in it's cousin, the Century 22, Ten-Tec replaced both the MRF-476 drivers and the MRF-475 finals with Mitsubishi 2SC1969, due to high failure rates. The 2SC1969 is also available from RF