Colin M1BUU's Homebrew Manhattan SST

 

Wow, especially on St. Patrick's day I think it is appropriate to say " 'tis a thing of beauty. "

Colin did a great job on his homebrew version of the SST transceiver. It looks like his is on 30 meters.   I especially liked his description of the troubleshooting that followed the construction.  the assist provided by AA7EE's blog was especially cool, and demonstrates the long-lasting power of internet-shared tribal knowledge. 

Colin wrote (on Facebook):  

I was inspired by Bill and his adventure with the SST-20, so I started gathering a few parts last year to build a Manhattan SST. I did a joint SOTA activation with a fellow homebrewer ham at the end of January and we started talking about classic portable CW rigs, it turned out that we both had an SST build on our 'list'. I was challenged to build the SST for the next joint SOTA activation!

It took a lot of effort and a few late nights but I did manage to produce a rig capable of making QSOs for a joint SOTA activation of Fair Snape Fell, G/SP-007. I'd done a solo activation of Pendle Hill G/SP-005 a few days before with the rig for a trial run and I discovered that the AF was very low. After some troubleshooting I noticed that I'd soldered the LM386 gain set capacitor to an incorrect pad. Doh! I fixed my error and the rig had much more gain.

I found that with the improved AF gain, the rig would squeal if the gain was turned up. I was ready to give up really, but after a cool off period, I began researching the issue and it turns out that it's very common and indeed I found posts from 1997 about it! It seems as though my recreation was so faithful to the original, I'd included the original flaws too! I added in a 0.1uF cap and resistor connected to pin 5 of the AF amp chip as per the suggestion on Dave AA7EE's blog and now the squealing has stopped.

I'd made 14 QSOs during the joint SOTA activation, so I considered my challenge to have been met! It's been a bit of an epic build!

73, Colin, M1BUU

SST -- QRP On The Beach

Up in a beach house on Cape Cod Bay in Massachusetts, I put the SST on 20 meters using an End-fed Half Wave antenna and QRP-guys tuner.  Conditions were pretty bad, with solar storms causing disturbances in propagation, but I did manage to get picked up by RBN skimmers in Iceland, Germany and Italy (see below).  And I had one nice QRP-QRP contact with DK4AN.

I was having trouble getting out until I used the oar to raise the central portion of the half wave antenna -- that's where the current is. 

Thanks again to Bob KD4EBM for sending me the SST.  

Santo Domingo Shack on 12th Floor Balcony -- SST QRP CW

June 2021.  We were in Santo Domingo, Dominican Republic.  At this point we were in a 12th floor apartment in the center of the city.  I would take my SST 20 meter CW transceiver and EFHW antenna out on the balcony.  I made no contacts from this location, but one of  my CQs was picked up by K9TM on the Reverse Beacon Network (see below).  All the other RBN spots were the result of calls from the eastern tip of the island. (Click on the RBN image for a clearer view.)

 

QRP - QRP Contact from Dominican Republic

It took some brass pounding on my homebrew key, but on May 28, 2021 I made a real QSO from the eastern tip of the island of Hispaniola.  KJ4R came back to my CQ near 14.060 MHz. I was running just 1-2 watts from my SST transceiver to an end-fed half wave antenna. Ed KJ4R was in South Carolina running 5 watts, also to an EFHW antenna.  TRGHS.  Thanks Ed.  And thanks to Bob Scott KD4EBM and Wayne Burdick N6KR.

VK3HN's Homebrew 30 Meter SST QRP Transceiver

It turns out that many people homebrewed SST rigs.  Here is Paul VK3HN's version.  Really nice. 

https://vk3hn.wordpress.com/2016/12/27/summit-prowler-two-a-scratch-built-30m-cw-transceiver-wilderness-sst-for-sota/