ON7MOR  2018 – MHL21336 13cm PA – 400mW -50dBc shoulders

This is a small 13cm PA for DATV

Gain 13cm 30 dB (20dB @ 23cm)
Supply 28 volt ca 0.5 Amp
Output 26dBm / 400 mW with ca 50dBc shoulders

MHL21336 on ebay ca €10,- (refurbished)

Update 04-2019

I use this amp after my Lime SDR mini using an attenuator

(MHL21336 = max 5dBm in)

I use it only for DATV -  till 400mW i get -50dBc schoulders so its very linear.
So using the device for SSB is not a problem till 400mW at all,
I suppose even 3watt is possible – i’ve never tried it.

VDD1  =  VDD2  =  28 volt  (30vdc max!)

I use a resistor (10ohm) between VDD1 and 2 so i can easy  measure both stages are ok.

Keep all connections as short as possible – you don’t want the amp to oscillate.


Disc capacitor (no leads) of about 1nF,
and 100n + 10uF elco in parallel

 I have measured the swr on input – its not that good on 13cm.
If you don’t need 30dB gain add an attenuator to the input.

More info....

Input SWR