Hi Richard, glad to hear the RockMite performed well. I built a RockMite 20 a couple of years ago. I haven’t had a contact with it yet. A self spot might be a good idea
I was thinking of ordering another RockMite for a different band, but I went to the Rishworth Convention and came home with a QRPme Super Tuna with crystals for 40m and 30m! QRPme - QRP FUN in cans, boxes and from scratch!
I’m not sure I’d be brave enough, but there is space for a trimmer cap to be able to turn the crystal oscillator into a VXO. The rig could then be put bang on 7.032 MHz using a 7.030MHz crystal. I’ve opened of real can of worms (tuna?) with this project as it’s only a transmitter, so I need to source (build) a suitable receiver and work out a switch over system. There is also need for a sidetone (could be combined with a keyer). I determined to operate the rig at least once from a summit!
Another thought of mine was to modify a RockMite to run on 17m. A RockMite relative, the HiMite worked on this band and was quite similar, so it would be a good starting point for values of the inductors etc.
Good luck with your 18MHz endeavours!
(If only someone would buy me a Hendricks BitX17 kit for Christmas!)
And it also looks like congrats are in order? That’s the completion of GW is it not? Pretty fine effort to have activated all summits in 3 of the 5 UK associations - G, GW and GD!
Well done G3CWI Richard.
Please tell me abt power and what battery type you use.
My rockmite I have put in 10.120Mhz xtal, running with a PP 9 volt battery bought in OZ in April 2010. Still possible to use it…But power is redused to under 100mW. This rig is my backup on activation. Saved med in Oz when my KX1 got sick. I got a Ten Tec 1330 on the g-qrp meting and when come home I took it up to my favorite summit for testing. Well as all guess when you try a used rig on a summit for the first time it didn’t work. TX no out only tone in headphones and RX only weak noise. Argg. But my rockmite got me 4qso so I activated the summit. ( No point due to multiple activation this year,)
Want to see who make most qso on a single 9v battery.? I may even set up a price for the winner…
Hope to see ore qso u sn dr om.
73 de LA1KHA Kjell
I was using a 4Ah 11.6V LiPo battery - rather larger than the Rockmite. A competition to make most QSOs with a 9V battery sounds like fun. …But what sort of 9V battery?
In reply to G3CWI:
Some years ago someone ran a challenge in parallel with the RSGB HF NFD to work as much using AA or D size dry cells, 12V worth but cannot remember the details. Steve GW4ALG entered this with his K2, if I remember correctly from one of the welsh summits (but he never seems to have uploaded the QSOs). He operated around 8 hours before the batteries finally gave up, towards the end running less than 1 watt. Might be interesting to reintroduce this sometime. Of course the K2 has a much lower quiescent current than many other rigs, mine will run for 8-10 hours from a 4AH gel cel at 5W in a contest.
Some years ago someone ran a challenge in parallel with the RSGB HF
NFD to work as much using AA or D size dry cells, 12V worth but
cannot remember the details.
…that someone was me. It was called the Power Management Challenge and was won by Don G3BJ.
The event will be celebrated with a beer (or two) at “Read Towers” this evening…
…as well as mine and Jimmy’s achievement of completing the County Armagh region in Northern Ireland, surely an even greater accomplishment than completing the whole of Wales!
Yes, I know it’s only five summits, but if you don’t believe me, check with the GI Association Manager Colin GI0RQK. Only Carrigatuke GI/CA-003 has been done any number of times in the past. The others have been avoided due to notorious car crime and antisocial behaviour in the parking spots, military presence on the summits (relatively recently decommissioned) and very non-trivial access on three of the five. No wonder it’s taken 8 years to see the first region completion for County Armagh!
So while Richard will be politely congratulated this evening, I will be basking in greater glory.
Want to see who make most qso on a single 9v battery.? I may even set
up a price for the winner…
Kjell
Now you have me hooked. I have started making a 30m rig especially for the challenge. It’s a sort of Rockmite but I will be looking at optimising it for low current.
Ok, it seems as though we have a project on our hands!
I think some basic rules need to be established for the competition. I assume that by 9v battery, we are talking about a PP3 / 6LR61 / Block battery.
Does the rig have to be a transceiver, i.e does the entire station have to be powered by one 9v battery,? Or does only the TX have to be powered by the 9v battery?
Is there a limit on battery capacity? Can you hunt for a really high performance battery or shall it be of a stated maximum capacity? Lithium?
I have a few QRP rigs on the bench at the moment and this thread is attracting my attention!
I had this idea for some time, And are most happy if any join.
I think it must be some thing like this :
Most qso on a PP3 battery contest.
All sota summits allowed.
A controversial available type of the PP3 9v battery. Alkalies ok.
No rechargebel battery.
One battery is allowed, and it should suply entier station.
Receiver, transmitter , tuner and keyer
(But battery for cell phone and flashlight not on this battery)
Any antenna type , but no fixed installation allowed.
I prefer that a qso is exchange of call-sign, rst and cfm/ rrr
Main rules must be fair play , honest log and have fun.
Log to qrp@online.no
The goal must be to show that even a small and simple station should be able to make contacts.
The power will be in qrpp class in most cases I believe.
The receiving end do most of the work so I hope they put in sharp filters now… hihi
I have more that 50qso on one battery on multiple activations.
So I hope all interested will try and enjoy the trill of qrpp.
All participants of our (LA) SOTA/ G-QRP trip this year bought a qrp kit.
Tests tonight show that the PA of a Rockmite is only 20% efficient at 8.5V so I am building an optimised PA for 8.5V operation. That will probably be a Class E fet pa (2N7000) but I am not sure how well it will work with a sinewave drive. More on that soon after I do some tests.
Update: my Class E version gives an efficiency of a little under 70% at 8.5 Volts - even with a sinewave drive. Pretty good for just adding two Cs and an L!
