[NLRS] Fwd: Re: Wanted SRF 3897 transistor

Fri Apr 10 22:02:00 EDT 2015

That's good information. I didn't remember the details but it was 
mentioned in the ARRL letter this week again.

73, Jerry, K0Cq

-------- Original Message --------
Subject: 	Re: [NLRS] Wanted SRF 3897 transistor
Date: 	Fri, 10 Apr 2015 20:48:30 -0500
From: 	John Toscano <tosca005 at umn.edu>
To: 	geraldj at netins.net

     *I found this at *http://www.rfconcepts.com/

     *Press Release*

(April 2, 2015) RKR Designs, LLC of Longmont Colorado has announced that
they have acquired the assets of Alpha Amplifier and TEN-TEC brands from
RF Concepts. RKR plans to expand the product line, while continuing to
service their customers that have enjoyed their products over the years.

Many years ago, I had my RFConcepts 2 meter amplifier serviced by Alpha
Amplifier (after they had bought out RFConcepts) and was quite pleased
with their service (price, turnaround time, etc.) It would be worth
contacting the new owners (RKR Designs) and see what they have to say
about it. I have 5 RFConcepts Power Amplifiers and love them all. Only
one of them has needed service in all the years I've owned them all, and
that was after it was pressed into temporary service on a local repeater
when the club's 2 meter PA blew up. We made sure to under-drive it but
the T/R relays didn't survive repeater duty. I hope you can get yours
going at full power again.

John, W0JT/5, EL09vu

On Fri, Apr 10, 2015 at 7:54 PM, Dr. Gerald N. Johnson
<geraldj at netins.net <mailto:geraldj at netins.net>> wrote:

     SRF is Motorola for special. Probably is a standard part specially
     selected or labeled. Its not a distributor part. RF Parts sometimes
     has cross referenced parts. Probably should be replaced in pairs. Is
     RF Concepts still alive? They ought to have replacement parts.
     Probably not since google showed a few exactly similar requests over
     the past decade.

forums.qrz.com/showthread.php?__271249-VHF-Mobile-Amp-__Transistors-Needed

<http://forums.qrz.com/showthread.php?271249-VHF-Mobile-Amp-Transistors-Needed>
     suggests MRF245 or NTE352 from 5 years ago.

     rec.ham-radio.narkive.com/__XgOV4PXR/looking-for-mrf-248
     <http://rec.ham-radio.narkive.com/XgOV4PXR/looking-for-mrf-248> had
     exactly the same problem you have and was looking for MRF248 some 8
     years ago.

     RFparts.com has MRF248.

     Several distributors claim to have the NTE352. Newark wants 2.5
     times RFparts price for the MRF248. Close to what I paid Radio City
     for a working Diawa amplifier last summer. Dan had a Mirage, but
     I've blown a Mirage with a bad relay and shorted at least one of the
     output transistors. Fortunately I had only paid $10 for it an an
     auction. I'm down on that Mirage design after spending time inside it.

     Some vintages of Mirage 160 watt amps use SRF3417, others use MRF247
     for 160 and 180 watt ratings.

     www.w6pql.com/klitzingamps/__2m10w180.htm
     <http://www.w6pql.com/klitzingamps/2m10w180.htm> old technology used
     MRF247. His latest product has a lot more power with LDMOS FETs. And
     pricey.
     www.w6pql.com/parts_i_can___provide.htm
     <http://www.w6pql.com/parts_i_can_provide.htm>

     73, Jerry, K0CQ

     On 4/10/2015 7:05 PM, Melvynkc0p--- via NLRS wrote:

         I have a RF Concepts RFC2-217 amplifier for 144 MHz. with 2 watt
         drive,
         supposed
         to be 170 watt out. Mine only puts out 65. Repair man in Twin
         Cities says
         one of the
         finals is burned out. Part is SRF 3897 according to the
         schematic, but
         currently
         not available (unobtainum).

         Does anyone have one, or could a pair of something else be used
         ? Or do I
         have
         another "almost works" ?

         73 Mel KC0P/R
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