I've just spent some time constructing a new 136 kHz aerial loading coil and the results are most disappointing. . It is of basket weave construction on a 7 pointed dowelled wooden former with a mean
LF group Many thanks for the useful advice and information. I have printed off all comments and will have a serious re-think about my loading coil design. The wooden dowels I used were 3/8 th inch so
Hello LF Group Many thanks for all comments and advice - most interesting. I drilled out the wooden dowels on the loading coil and replaced them with lengths of 15 mm plastic water pipe. I was unable
Hello LF Group I use a simple home built D.C. receiver for the 136 kHz band and the selectivity is rather poor. I built G3LNP's excellent rx loop when it was first published in RadCom in 1999 and it
Hello LF Group Very many thanks for all comments and advice about my telephone wire problems. After due deliberation I shall take the easy way out and cut a metre or two from the aerial and resite th
LF Group Just a thought - having used QRSS-3 for a few weeks I notice that K is used exclusively and KN not at all. I often catch the end of a transmission and consequently cannot tell whether the st
Many thanks Rik, I'll give it a try. 73 Chris G3XIZ Chris, Ok about KN. But in QRSS or DFCW mode you don't have to waste time and wait for a QSO to end before calling one of the stations. Just move u
Many thanks Alan, All noted with interest. I am always apprehensive that I may not 'see' a DX station and inadvertently call over the top of him. Thus I tend to reply on a frequency some way removed
Johan and LF Group I like the idea of a binary code. One could also use normal QRSS, a dot being a 'space' and a dash a 'mark'. Thus one would have a code book of 127 phrases (or better still 256 for
YU7AR was calling CQ on QRSS-3 at about 2020 Z last night F6BWO answered him After a few minutes YU7AR sent " ? AGN " but F6BWO had I suspect gone by then. ON7ZO then called YU7AR but got no reply. A
There's an interesting item for sale on E-Bay which may be useful for LF . . ENI PL3G LOW FREQUENCY RF GENERATOR It says it's range is from 100 - 450 KHz and has an output of 0 - 3000 watts !! Unfort
I'll put out some CW CQ calls between 0800 and 1000 GMT this Saturday and Sunday around about 136.3 kHz. M0FMT says he'll try to join me for a QSO. We're both QRP but if you can hear us we'd welcome
Hi Dick, Very useful information and encouraging too that your TX is so similar to mine. I will try that resistor mod with my last few IRF520 FET's and I have now ordered a TUBE of IRF630's (200 volt
Thanks for the advice Alan, It's looking like a higher voltage device may be the answer. My existing TX uses the same FET's but only runs at 24 volts. They may well be running right on their limit an
Thanks for the advice Jeff, All points noted. I must confess that all of the published designs seem to use a logic driver IC. I must be being awkward using an inductor :-( Maybe I'd better stick to a
Many thanks Rik, I shall put in an order for some more robust fet's. I would have thought that the aerial system was resonant but something seems to have changed ! 73 Chris G3XIZ Chris, if the load d
The PA FET's in my new home brew transmitter keep exploding ! I'm using push-pull IRF520's rated at 100 V Vds and my supply is 30 volts. I am careful not to exceed the V gs. The gates are driven with
Many thanks Dave, All noted with interest and I should have no trouble now. I saw your CQ on DFCW last night, must have been about 8 'ish. I was tweaking my new RX and you were of course a colossal s
Many thanks for the rapid and informative response Alan. I'd just drawn out the circuit you described then found the attachment later - doh ! The drawings were the same so your description was fine.
My new LF TX is nearly finished and I would like to add the option of DFCW. I was thinking of just placing a varicap diode in parallel with the crystal and thus pulling the frequency for achieving th
