On 17 April 2011 19:07, Chris Osborn <[email protected]> wrote:

LF, I went QRT on VLF at about 17.00Z today. Many thanks for all reports over the weekend and I shall give a summary later in the week. Balloon (and kite) launching from my home QTH is difficult and at times quite stressful. I have to be ever vigilant that the balloons (or kite) don't hit local houses (TV / FM radio aerials) or come down in the adjacent playing field (children + EHT !) I have a reasonable PA which if properly matched could give several hundred watts of RF. At present I get at best about 140 watts. I am still using the mains matching transformer between the PA and the loading coil and this has a step-up ratio of 1:24 Energizing the PA with a higher voltage than its present 30V is not an option as the matching transformer is already running over-voltage and would doubtless break down. It has been suggested that I use link coupling to the loading coil from the PA but the one time I tried this caused damage to both the PA and the coil, so you will sympathise with my reluctance to try that again! I will continue for a few weeks and see if I manage to get 'real' success with the balloons or kite assisted aerials. I was considering taking apart an old PC PSU and using the output transformer from that instead on my present iron-laminated mains transformer. I believe that PC types will be more suitable and handle higher voltages. I plan to transmit over the Easter holiday but beyond that I am uncertain. I have a plan to try /P during the summer but this depends on gaining the permission of the land owner, which I am waiting for at present. I am getting consistent reports from my 'regulars' but now need a step change in my VLF progress. 73 Chris G3XIZ