Getting 800mw out from your Rock-Mite
I recommend using a 2N2219 as a replacement for Q6.
I actually used an NTE equivelant which is an NTE 123.
You can just make out the '123' in the picture above.
To run up the gain a bit more, I replaced R18 with a 2.2 ohm resistor.
This yields about 800mw on 40 meters, about 700mw on 30 meters and
about 750mw on 20 meters.
I have read that at least one person has tried a variety of 2N2219's
and was able to find one that yielded a full watt. YMMV.
--> A word of caution: Some RM-40 owners have reported burning up L1.
This happens when Q6 draws too much current. Rock-Mites
are very sensitive to SWR. If you modify your radio for higher
output, be sure to use a antenna tuner or a resonant antenna so that the rig
is 'seeing' a 50 ohm load.
Also, replacing L1 with a torroid or a higher rated choke can be helpful.
I did this on my RM-40.
Torroid(40 meters): 12 turns of 26awg on a T37-43.
*Choke(40 meters): Mouser P/N 423-23-100 is rated at 680ma
and is only slightly larger than the 'stock' choke.
* Note - I understand that the newer RM/40's now ship with the
higher rated choke.
I have received a couple of comments on my lack of heatsinks.
Since I run with a matched antenna the I have not had a problem
with overheating. The cans get hot... but not scorching, so I decided
to forgo the heatsinks. Other ops have not been so lucky so you might want
to think about heat sinks on your own Rock-Mite.
Many thanks to Chuck Carpenter, W5USJ, for all of his experimenting in this area.