G/LD-003, M1BUU/P

A couple of weeks ago, I got the idea into my head that I’d like to build another RockMite to give away.

I had most parts in stock, except for some crystals. The inductors that I had on hand were suitable for 30m, so I ordered some 10.116MHz crystals from Graham, G3MFJ at the G-QRP Club.

I built the board in about 3 hours, split over three sessions as and when I could find time to go into the shack.

I have altered the PIC code to start up at a faster default speed(~20wpm), it just makes it easier when on the hill, the default 13wpm is a bit sedate. I dug out my old PIC programmer and attempted to remember how to program a PIC. The 12C508 is a OTP (one time program) part, which means you’ve got one chance to get it right! It is possible to use a flash chip instead, but I use the original type to be more correct. Thankfully the programming worked on the first shot.

The smoke test went fine, the rig fired up first time and I was seeing a shade over 400mW with no reverse polarity diode at 12v.

I ordered some mint tins via Amazon and I recieved animal themed tins instead of the London themed ones I had selected! Oh well, the owl tin looked quite interesting and unusual.

The weather forecast for Sunday looked quite good and my son had been wanting to conquer Helvellyn G/LD-003. I didn’t want to let an opportunity to activate Helvellyn in decent weather go to waste.

We arrived at Swirls car park to discover that the parking ticket machine was working and only accepting coins. Several previous times I’ve been in winter and the parking machine wasn’t in use. Grrr! I’d overlooked that detail in my rushed planning the night before. We got back in the car in order to head to a cash machine and shop in order to get some coins to feed the greedy parking meter (£7). My son was quick thinking and steered me to Grasmere where we found a Co-op with a free cash machine.

Back at the car park, I felt lucky to find a space to squeeze in to and we went to feed the hungry parking machine. We’d lost half an hour just trying to park the car.

I was slightly late getting on air, but only by about 20 mins. The snow was mostly gone, only a strip on the edges.

My son taking a picture

I found 30m to be busy but I called CQ anyway, I wanted to prove that the radio worked. I did manage about 6 contacts before the QRM got unbearable. The wind chill was much worse than I expected, I was soon shivering, and my son was walking about in his down jacket trying to keep warm. I had wanted to try to chase Richard @G4TGJ on G/NP-008, so I asked my son to check SOTAwatch for a spot. The phone signal was intermittent but my son eventually found a spot for G4TGJ/p on 20m. My dipole was 30m/20m linked antenna fortunately and I’d taken an MTR-2B as a back up rig. I fired up the MTR-2B on 20m and I heard Richard straight away. It didn’t take many calls to manage an S2S.

It was extremely cold, so on this occasion I elected to get moving and off the hill, especially as I had my son to think about too. Maybe I’ll go back to Helvellyn in summer and spend a bit longer on the summit.

I was pleased with the little home made RockMite, it worked just as expected. I got home and packaged the rig ready for sending to it’s new owner. The rig was mailed Monday morning and the new owner has already had it on air today (Tuesday!).

Three random photos -

It was a beautiful day but very cold.

73, Colin


Hopefully the new owner will get to use is soon.The perfect setup for a 9v battery activation.

Snow seems to have gone early this year, maybe we’ll get some more.Some of the pictures the felltop assessors have been putting up when it was covered in snow looked horrendous. Ice covered in snow.Ideal for a fall.

Must get back there soon

For 9v operation, it’s better to reduce the value of the resistors in the zener shunts, this reduces the overall current requirement.

Dave K1SWL adds a note to his RockMite builder’s guide -

Better yet, get rid of the zener shunts and use a 5v regulator instead -

Yes, I was rather hoping to go up Helvellyn under snowy conditions but you can’t have everything!

73, Colin


Very little shelter on Helvellyn with the sharp Easterly drop off, not a great summit for HF radio except on a warm, windless day. I’ve been shivering in mid-summer if the wind is up.

Great job and one ticked off, and a good points haul @M1BUU!