White Hill G/SP-006 (Magic of radio)

I’m a big fan of home construction and simple QRP transceivers. During the Covid lockdown at the end of 2020, I made my first attempts at drawing PCBs on the computer. I used the traditional RockMite circuit for one of my boards, the firmware and schematic are freely available on the Internet and on the ARRL Handbook CD.

I have built three of my tribute RockMites so far but I hadn’t actually tried them on air. I don’t operate from home, so I’d only tested the rigs into a dummy load in the shack.

The WX was great today and the SFI was up quite a bit so I decided to do a quick activation of White Hill G/SP-006 with my QRPp rigs.

I did the school runs and then did a few domestic chores before heading out of the house at just after 10am local. I reached the parking place at ‘Cross of Greet’ at 1030am. I reckoned that 45 minutes plus 15 minutes of setting up would see me on air at around 1130am local (1030utc).

The route is usually a non stop bog and I wasn’t prepared to risk wearing anything else but wellies. The ground was very soft in places but with care, hiking boots would have been fine.

I reached the summit by about 1110am local and it took only 10 minutes to put up the Bandhopper 3 dipole. The sun was beating down and there was very little, if any, breeze.

I first fired up my LA1KHA challenge 9v RockMite and although I’d packed the wrong earphones (doh!), I was elated when Bruno HB9CBR/P called me for an S2S with HV/VD-037. F4WBN was his usual very strong signal and I received a 599 in return. I’m not sure whether I really was 599 or whether it was just a contest style report! Lars SA4BLM called me with a good signal and then I worked OH3GZ, who was slightly weaker. These chasers must have super duper receivers to receive my 150mW!

My little PP3 battery now has over 100 QSOs to it’s credit and it’s still going strong. I believe I first started using the battery in 2012!

My home brew rig will turn 10 at the end of this year and I’m quite proud of it. The only problem I’ve had is the BNC connector working loose.

I next fired up my new home brew 20m rig. The rig put out about 300 - 350mW during testing in the shack.
I called CQ for quite a while but then LB6GG responded with a really good signal. I have to say that I was very happy at that point- the first QSO on a home made radio is always special to me. I was relieved that the TX/RX shift was working well, I find it difficult to measure it precisely in the shack and using a frequency counter tends to upset the rig and the readings are them meaningless anyway.

Unfortunately after my first QSO, another station starting calling CQ on my frequency (or at least very near). I continued calling CQ as my rig is rock bound. I heard SP9AMH calling me but unfortunately due to the weak signal and little bit of QRM I wasn’t able to complete the QSO :frowning:. Sorry Mariusz, I did try for a few minutes.
Thankfully the QRM disappeared and I was able to work SP6BOW and EA2DT. With three in the log, I was then driven to try to get a 4th QSO which would’ve counted as a qualification.

After a few more CQs, I was delighted to be called by Ignacio @EA2BD. I wanted to express my apologies for my weak signal, so I sent “PWR PWR 300mW 300mW”, to which Ignacio responded “wow”. This was another one of those special QSOs that I’ll remember for a long time.

I know that I say it far too often but this radio hobby really fires me up and I’m a true believer in ‘the magic of radio’. I’m only following in other people’s footsteps but I created a device from scratch and then used it to contact a friend in Spain. It doesn’t get much better, does it?

73, Colin


Thanks for a great report, and congratulations on making your activation with your home-brew kit. Inspiring stuff and completely agree with you on the ‘magic of radio’.

73 - Matthew M0JSB


Congrats, Colin, for the success.
I saw you spotted on 30m, went there and heard nothing. Later I was out so I missed your pass on 20m. I would have liked making QSO with you on that new QRPP rig. Ignacio told me this afternoon about your QSO. Great both of you!



Love the one in the tobacco tin. :slight_smile: Is it literally fixed frequency and was it made from a kit? I’ve found someone selling kits for $50 although for about that you can get a QCX Mini - but they don’t run off a PP9. :slight_smile:

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Thanks Colin for your report and photos. Great effort on your part using home built equipment. Well done. :grinning:

73 de Geoff vk3sq

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Hi John,

The radio is in a Stewarts mint tin.

The rig is home brew, so no, not a kit. I drew the PCB using Kicad and had a small batch of boards made by JLCPCB.

The rig runs off 12v. The design uses zener shunt regulators to give low voltage supplies for the mixer chip (NE/SA/602/612) and PIC (keyer). To run from 9v, ideally the shunt regulator resistors need changing.

In my 9v modified rigs I run a single low drop out 5v regulator to power the PIC and mixer in place of the shunt regulators. I also use a different op amp for the audio.

A RockMite kit is available from QRPme and possibly Kanga Products when I re-opens after change of ownership.

Yes, you’re right, the QCX mini kit is difficult to compete with considering features to price ratio. I have another QCX-mini kit waiting to be built.

A RockMite can work out to be quite expensive to build once you’ve factored in a PIC, a mixer, a varactor, connectors, switch and chokes, non of those parts are especially cheap.

I dread to think how much money I’ve spent on RockMites… :laughing:

73, Colin

Oh, and later edit…

The frequency is set by the oscillator crystal. It is possible to use a socket and use different crystals within the same band, this is what I do with my 9v challenge rig. In the mint tin radios I solder the crystals in because there isn’t enough space to include a socket. The crystal is pulled by a varactor to provide an RX shift, so you can hear a replying station away from zero beat. Because the shift function is actuated by the PIC, it’s possible to swap the TX and RX frequencies over using the firmware, this sort of creates two ‘channels’ of operation several hundred Hertz apart.



Many thanks. That’s a brilliant project. I haven’t tried designing and getting a board made.

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Or altoids :wink: £5 a tin and the mintiest breath on the air.
Well done Colin!

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What a great collection!

I saw the spot, heard the QSO with Bruno and could tell when you were transmitting, but unfortunately you were too weak to even attempt a QSO. Really pleased to see that you are getting out again with your homebrew kit.

73, Gerald

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Well done Colin,
I have a 40m CW rig I made some years ago, but it is 100W QSK and has a HB 350Hz CW filter. it is very satisfying to know it is all your own work even when it drifts a bit, but it is too heavy for portable use.

Gud Stuff


I think we need a PP3 S2S challenge day.

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