[NLRS] Motorola SGTF1040A amplifier for sale

[David Palm]

I am (with some sadness) selling my Motorola SGTF1040A amplifier, which is
capable of up to 150 watts on 900 MHz.  The cool thing about this
particular amplifier is that it can put out more than 100 watts with as
little as 50 mW of drive.  This runs off 24-26 VDC.

I had intended to get this amplifier up and going as part of a serious base
station with power on 900 MHz.  But in the end I see my future UHF
operation as geared toward roving (yes, life is starting to settle down).
I hope you will find a great place for it in your own UHF line-up.  I'm
asking $135, shipped.  Can send photos if you wish.

AA9IL says this about these amplifiers:

This amp uses a two stage preamp and a tuned input, will cover a wide
range.  The drive required is as low as 50 mW for 100+W output. I tried
this amp with 5W drive for a short time, with 150W output, with nothing
smoking.  Power supply required is approx. 26VDC @ 15A.

These class AB linear amplifiers were made by Motorola for use in the 800
MHz cellular band.  They will also work very well in the 900 MHz band with
some minor limitations.

The amplifier board typical for most of the units listed here is a MRF897
driver and a MRF899 final.  The MRF899 final  transistors are rated for
150W PEP.  Approximately 4-7W drive will be needed for full output.  The
SGTF1021B and SGTF1040 have additional driver stages, and can be driven
with miliwatts.  Their original application used only a fraction of the
power available.

Full output is typically achieved up to 910 MHz.  Going higher in frequency
the output starts to drop, due to the circulators or isolators used.
Results vary quite a bit between the same type units. The isolators are not
easy to remove.  Some minor tuning can be accomplished with a magnet.  The
transistors are rated up to 960 MHz.
73,

David  W9HQ