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!
In reply to G3CWI:
Hi Richard…I’m building a Rockmite40. Just curious…was that 20% efficiency at 8.5 volts observed using the hint below, or just reduced supply voltage on standard Rockmite PCB layout???
• Reduced Supply voltage
The Rock-mite will run on a 9V battery if R1
and R8 are changed from 1K ohms to 470
ohms. This change increases (receiver)
current consumption from ~25 mA to 40 mA
when using a 12-14V supply.
R1 and R8 are dropper resistors for the PIC and the NE602. Reducing them will do nothing for the efficiency of the transmitter. 40mA or even 25mA is far more receiver current than is actually required. I will be aiming for less than 10mA on RX.
In reply to G3CWI:
British ingenuity may bee greate.But my concept at present time is :
Even the most stupid farmer may get big potato’s.
I stick to this theory for present time. Hi.
But I have plans for the winter to improve my Rockmite with xtals for 10.106, 10.116 and the favorite 10.120 Some kind of swishing of these and a audio filter. And may be optimizing the rig for 9v. But will try to keep power to under 100mW
