Last ship date of MRF-247's was November 2003. Date codes after that
are most likely counterfeit.
The MRF-247 was one off the highest running RFR power parts Moto-Semi
(now Freescale) made. Another option is the Motorola in house number,
which was 4884411L04. They were screened to a slightly higher standard than
the generic MRF-247 and can often be found at a better price. On the street
they are simply marked as M1104 or M11L04.
Regarding soft failures in amps (where one part is known dead instead of
the pair or a quad set, if the power is less than half rated, odds are the
alternate part(s) is damaged too. Another factor is how long one might have
tried to use the amp with the damaged part or parts. Good luck with it...
73 Mike K9MK
-----Original Message-----
From: vhfcontesting-bounces@contesting.com
[mailto:vhfcontesting-bounces@contesting.com] On Behalf Of Mike Benonis
Sent: Thursday, April 14, 2011 11:51 PM
To: VHF Contesting Reflector
Subject: Re: [VHFcontesting] [Mw] How do you know if an MRF-247 is real?
This is a good question that I had as well. I just bought a 180W 2m
amplifier that I know will need a new MRF247, and I'm wondering whether to
buy one or two on eBay, or get the new 2SC series replacement part as a pair
from RFParts.com...
Mike
On 14 Apr 2011, at 21:01 , John T Rose wrote:
> It isn't just counterfeit parts to watch out for. At times a large
> quantity of the parts that failed to meet specification gets out to the
> market. Some thing I am suffering through at work. An older design with
> an IC that was last made 6 years ago. Some of the rework people cringe
> when I head in their direction!
> On Thu, 14 Apr 2011 15:22:14 -0500 "Mike & Becca Krzystyniak"
> <k9mk@flash.net> writes:
>> I looked at the item on eBay and they pass the common sense test but
>> I have
>> heard rumors of counterfit parts coming from China where performance
>> was off
>> from the branded part.
>>
>> The MRF-247's were built in Malaysia from 1999 through 2003 and the
>> last
>> ship date was around week 47 of 2003.
>>
>> So if these are legitimate MRF247's they were made in the one of the
>> last
>> production runs.
>>
>> 73's Mike K9MK
>>
>>
>>
>> -----Original Message-----
>> From: microwave-bounces@lists.valinet.com
>> [mailto:microwave-bounces@lists.valinet.com] On Behalf Of John
>> D'Ausilio
>> Sent: Thursday, April 14, 2011 2:45 PM
>> To: Microwave; (Radio) VHF Contesting
>> Subject: [Mw] How do you know if an MRF-247 is real?
>>
>> for instance, item 180557984917 on ebay .. too good to be true?
>> I've
>> got a Mirage and a TE, both with bad transistors, that I'd love to
>> get
>> working again .. I wouldn't touch the "UK" variety, but how does
>> one
>> tell if a Motorola-marked part is real or not?
>>
>> de w1rt/john
>> _______________________________________________
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>>
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>
>
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Best regards,
Mike Benonis
mike@benonis.net
KI4RIX
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