The Ranger Pre-amp Adventure

Tweetbutton tweet

k7ip Wed, 07/22/2009 - 11:21

Last year at the Puyallup junque fair, I picked up a Mirage amp for six meters that I have been using for meteor scatter and sporadic-E. The internal preamp in this brick has a miserable reputation, and the copy I have seems to be no exception. Lots of noise, not much amplification, so I ordered a DEMI 6MLNAK to retrofit into it. Ever the habitually lazy procrastinator, that little kit has now been buried in the bottom of my junk box for more than a year. The recent flurry of mountaintopping on six has prompted me to revisit where I'm going to stick it, and the Ranger is now the top candidate.

I have non-ham activities scheduled for this weekend, so there won't be time to dig out the soldering station and build the kit, but I did manage to rip off an email to DEMI tech support and ask them if they thought the isolation that the RLS-135 PIN diodes in the Ranger T/R switching arrangement would be enough to keep from roasting the GaAsFET in the preamp. Their opinion is that it might be a good idea to put another PIN switch in the path along with the preamp, so after some math and catalog shopping I feel encouraged to take a whack at building a small SMT board with diode, choke, and bias resistor thereon.

This place will keep track of my efforts as this project progresses. That makes a total of at least four kits that I haven't yet built. The PK232 kits are probably going to get shoved back to the bottom of the heap in favor of this project and the Softrock stuff.

Stay tuned for an update on the good stuff....