SM3437 3.4 GHz amplifier everything you what to know

23cm, 2.4/3.4/5.7/10/24/47 GHz and above - antennas, propagation, operating, etc. Includes Optical communications, with light,
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SM3437 3.4 GHz amplifier everything you what to know

Post by VE2OLM » Mon Mar 11, 2019 7:00 am

Hi i try to collect all information to a single place

so here the datasheet ( thank to zl2bkc )

input is 0dbm and not what to buy a attenuator for put on my kuhne MKU 34 G3 that drive 400mw
so i mod the first gain stage remove MMIC and remplace by 20 DB PAD. (17 db may better option )
dir coupler

Then amplifier i have not have PWR and REV option and i need it so ....
feedtroug cap is stock from digi-key 410-1034-ND 2425-001-X5U0-101AALF
then need 250 to 500 ohm 0805 resistor on directional coupleur to match sensitivity you need (250 ohm = ~3.3V for 20W)
for REV is bit more complicated need to replace the circulator for one that have 30db pad instead of 50Ohm load
inout mod
next is PTT input , Datasheet said it 5V TTL , find on web to put 4.7K serit resistor for 12V input , but i chose to dray schematic of input circuit
this show that it may take 12V from sequencer or TX relay of transverter whit no mod
input circuit
probably final mod is that AMP is class "A" Bias so lot of heat , i may check later for put it in class AB for less heat dissipation and efficiency

if you have anything feel free to add it

final feet datasheet ... FLL300IP-4

predriver datasheet ... evices.pdf

predriver datasheet ... 107ME.html

best 73! Marc L. VE2PN / VE2OLM

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Location: Southern Tasmania

Re: SM3437 3.4 GHz amplifier everything you what to know

Post by VK7HH » Tue Mar 12, 2019 9:00 am

Thanks for your post. I've just got my SM3437 working. It's outputting 22W for 0dBm drive.

Just waiting on my external attenuators so I can pop them on the output of my transverter.

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