[NLRS] Wanted SRF 3897 transistor

[Dr. Gerald N. Johnson]

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 
suggests MRF245 or NTE352 from 5 years ago.

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 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

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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