[CQ-Contest] Need a Yaesu FT-100D VHF/UHF amplifier repair source
N6KI Dennis Vernacchia
n6ki_73 at sbcglobal.net
Sun Sep 10 20:55:31 EDT 2006
Does anyone know anyone that knows something about designing and repairing
This person would have to be a super-tech or have some design experience as
here is the situation.
A ham friend has a FT-100D HF/VHF/UHF mobile transceiver. He blew up the
device. Yaesu no longer has these Motorola devices in stock and apparently
Motorola is no longer
making them. There is NO direct substitute device.
This device is the output stage for 2 mtrs and 70 cM bands ( 50W on 2 mtrs
and 35 W on 440 mHz I believe )
It is not one of the common modules ones sees in most VHF/UHF mobile Xcvrs.
A call to RF Parts in San Marcos yielded a device that has same form factor
and as good an
electrical parameter match as one might find.
A local ham who does a lot of servicing and has a great deal of test RF
knowledge and test equipment, installed
the substitute device but, unfortunately the device does amplify but due to
parameter differences etc - it also tends to go into
oscillation and tries to destroy itself. This is a common event in
when trying to substitute a device that doesn't exactly match the original.
What is needed is someone that has a good RF test equip setup and knowledge
to figure out
what circuit mods would be needed to stop the oscillation ( if even possible ).
If someone can solve this problem, there are plenty of FT-100D rigs with
blown VHF/UHF devices
that need someone who can effect a repair. according to info from Internet
When you send your FT-100D into Yaesu with this problem, I understand you just
get the rig back marked "Not Repairable". I guess Motorola bailing out on
making the device
....probably a minimum quantity issue, has now cause a nasty ripple in
to affect a repair.
I bet there a bunch of owners of the FT-100Ds with blown VHF/UHF PAs
that are not happy campers at the moment !
( and I am sure some future blown amps will occur ! )
Any help appreciated.
I have no pecuniary interest in this matter
73, Dennis N6KI
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