[ARC5] "Re-Banding" SCR-274N

[Mike Everette]

Tripling in the final -- if you feel so brave -- with a BC-457 will get you to 20 meters.  Yes, it'll work.  But you need to be very careful when tuning up.  Best to modify the transmitter (OH, the HORROR! SCREAMS!!!) by adding a tripler stage between the oscillator and PA.

Back in the day, that's how we learned....

73
Mike
WA4DLF
--------------------------------------------
On Tue, 3/25/14, Glen Zook <gzook at yahoo.com> wrote:

 Subject: Re: [ARC5] "Re-Banding" SCR-274N
 To: "Robert Rode" <midnitetoaker58 at gmail.com>, "David Stinson" <arc5 at ix.netcom.com>
 Cc: "ARC-5" <arc5 at mailman.qth.net>
 Date: Tuesday, March 25, 2014, 11:10 AM
 
 Using a BC-457, and then doubling in
 the final amplifier, would give a 30-meter transmitter.
  Remember, a lot of the old "Novice Class" transmitters
 doubled in the final to get to 10-meters and that worked
 pretty well.
  
 Glen, K9STH
 
 
 Website:  http://k9sth.com
 
 
 
 On Tuesday, March 25, 2014 10:00 AM, Robert Rode <midnitetoaker58 at gmail.com>
 wrote:
  
 ...Dave, just sayin', first day 30 meters came available , I
 heard a guy
 using an ARC-5,...have no idea what model, but I thot it was
 very cool  !
 Have fun hope to hear u there,..W9ESX/Robert..
 
 
 On Mon, Mar 24, 2014 at 7:13 AM, David Stinson <arc5 at ix.netcom.com>
 wrote:
 
 > At a recent estate sale, I picked-up some cosmetically
 rough
 > but otherwise complete and unhacked 274N transmitters-
 > a 457, a 458 and a 459.  Putting the 457 and 458 on
 their closest ham band
 > is a simple matter of re-tuning the MO and PA padders.
 > Worked well.  When I got to the 459, I decided to try
 something different
 > and moved it UP to 30 Meters
 > using the same procedure.
 >
 > Turns-out the 274N transmitter can work as well
 > at 10.1 MC as it does at 7.0 MC.  When installed in
 the rack per original,
 > there is quite a bit of chirp.
 > However, if run "stand-alone" by the "Boatanchor Bob"
 method- disconnect
 > the Antenna relay, roll the contact so the antenna is
 always connected,
 > adjust the Selector relay contacts so the PA cathodes
 > make before the Oscillator contact,
 > key the rig with the Selector relay-
 > there was very little chirp and the transmitter was
 stable on frequency.
 > I'm keeping this one on 10.1 MC for fun.
 >
 > 73 DE Dave AB5S
 >
 >
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