Other SOTA sites: SOTAwatch | SOTA Home | Database | Video | Photos | Shop | Mapping | FAQs | Facebook | Contact SOTA

30w Mosfet amplifier


#1

Does anybody have a copy of part 2 (QST April 1999) of the article by WA2EBY “A broadband HF Amplifier using low cost power Mosfets”. I have part 1, the Mosfets, but not the crucial part 2 of the article!! I have seen a reference to it on the ARRL download site but am not a member so cant get in. :frowning:
Any help to get heard from the hills appreciated.

Thanks

Tim


#2

In reply to G4YTD:

http://www.falara.org/tektalk/VALDEZ2.pdf

Similar but bipolars.

http://site.hfprojectsyahoo.com/hf_packer-amp

Based on the 1999 QST article but with some clever enhancements.


#3

In reply to G3CWI:Thanks again Richard. I may as well just e-mail you with any questions, you are usualy the first to send a reply! Lol

I should have said in the original post:- or any ideas for a 30w-ish either mono band or multiband solid state amp. The FT817 just needs a bit of a hand sometimes for SSB use.

:wink:


#4

In reply to G4YTD:

I use an HFpacker and have found it to be very suitable for SOTA. I mentioned it in Radcom a couple of months back in an article devoted to the choices available for higher-power portable radio (with SOTA in mind).

There were several other suggestions in the article.

73

Richard
G3CWI


#5

In reply to G3CWI:

Likewise I have the HFPacker. Came as a kit from the US. Good value and excellent build instructions.

Nice and light.

Great on CW. Really great on CW.

I do use it on SSB (mostly 60m) if it’s really needed, but the linearity isn’t fabulous. Apparently it’s a limitation of the design/devices. Cranking up the bias helps it sound a bit better, but not too far of course… Having said all that, it does the job if the band’s noisy or the propagation isn’t good.

I’ve added a ‘PTT’ input and plug that into the '817s ACC socket to hard switch the amp from Rx to Tx and back. This saves waiting for the RF vox to go back to receive which can be a pain on a summit when things are busy!

  1. Ian.

#6

Thanks Ian
I have heard good reports about this PA from several places now so may just give it a go.

Thanks for the info on the mods too.

73

Tim