Mitsubishi Power Amplifier modules

[g4saq]

Heads up that the 23cms module (18Watt) has been discontinued. Enigma have just got the last few in stock but the price is now over £100. Nick at Enigma advised me that he thinks other modules in the series will be discontinued soon (and several Mitsubishi power transistors).
73, Russ.

[g6hfs]

Hi,

Will have to keep this version then

[Pa3fbx]

I have some bad results with this module anyway.
I have 2 ra18H1213G in use witch are similar price range but much higher Gain and better linearity
I get easy 15 watt datv out of them.
With only 200mw in on 15Volt.

Benno

[g6hfs]

Hi,

My original gives 18w

[G3GJA]

But how far down from the peak are the shoulders?

The bipolar M57762 and the MOSFET RA18H1213G perform well in DATV service provided you keep the power output to 5W and 6W RMS respectively. Meters like the CN-801 read about 13% high on a DATV signal.

The gain of the bipolar is about 13dB and the MOSFET version is around 23dB.

Clive G3GJA

[g4saq]

It was remiss of me not to have given the module number to avoid confusion. I was referring to the RA18H1213G (https://enigma-shop.com/products/mitsub ... ier-module ). I was not aware of other variants until reading the above posts.
I accept the advice that power must be kept low for linearity but this module remains the easiest way of producing useful power at 23cms. I have been unable to find any alternative solution. Ideas will be much appreciated.
73,
Russ.

[radiogareth]

I built the G4BAO (Radcom 2009??) design but that needs a pre-driver. It did deliver 25 watts of TV though, before I TX'ed without an antenna. That let the smoke out and I have yet to fix it. Jim G7NTG did a design and PCB a while back, from memory it was even better than that. On my build list...
Don't think 'kits' as such remain available for these, but no harm in asking around I guess....
Must get on with one as I only have around 5 watts ATM.
Gareth

[g4saq]

Hi Gareth, sorry to hear of your accident with the module. Expensive! Enigma sell a fully populated PCB to go with these modules. It's only about £8 if purchased with a module. As for a driver, the MiniCircuits PHA-102+ is a good candidate but it might need 2 of them cascaded to get the gain. Paul Wade, W1GHZ, sells some nice little PCBs to use with these MMICs.
73, Russ.

[radiogareth]

Thanks Russ, it was actually a single device PA that I blew up, not a module. Mine is labelled with the required Pluto drive level and '5 Watts DVB' as a realistic output. Beyond that it got a bit of a mess. I'm pre-driving mine with a generic '5189' amp and it was written up in I think Winter 2021 CQTV - the "Boxer amp".
This is the amp I'm referring to https://github.com/g4bao/23cm-45W-PA

Gareth

[g4saq]

Sorry Gareth, I clearly didn't read your message properly! Thanks for the info re the G4BAO design. The special PCB makes things tricky. I'll have to keep a look out. In the meantime, I'm building the Mitsubishi RA30H1213G amp. Benno's comments are encouraging.
73, Russ.