MRF-421 on 6M

[VK4HJ]

Morning all,
Has anyone had success using MRF-421 on 50 MHz?
Tnx in anticipation.
Chris VK4HJ

[ZL2WHO]

Hi.
I wouldn't go there, look at the power gain vs freq chart here... http://www.datasheetcatalog.com/datashe ... F421.shtml
The gain is down at 30 MHz so i would suspect at 50MHz its very poor.
Save you $$ and make your next PA with LDMOS.. big boys toys !! These things are magic.

73
Mark
2WHO

[VK4HJ]

Thanks for your reply Mark.
I asked the question because other hf transistors like the mrf454 work well at 50 MHz
but are only characterised up to 30 MHz.

I just want an easy booster for a 5w sdr and have an old codan PA board that might
be worth playing with if the finals MRF-421's will pump up to 6m.

Chris.

[VK5ZLR]

Coincidentally, just playing with a MRF421 based codan PA on the bench as we speak.

Not directly relevant to 6m, but the Codan PA's generally don't drive the MRF421's too hard, there seems to be quite a lot extra to be had without letting the smoke out ( yet ! ).

[VK2XAX]

Stick it on the bench and try it!

What have you got to lose ?

cheers

Tim

[VK4TI]

I do hope the smoke stays inside the device

[VK3IH]

watch the drive levels on those Codan PA's they don't need much or they will take up smoking....................