In reply to M6WOW:
If you are using none pvc covered wire the lengths will be slighly longer so over estimate and fold the excess back untill you are confident both dipoles are in resonance.
When I did my inital tests I went to a local playing field where there was plenty of space to reduce the possiblity of close by objects causing problems.
The all in weight of the antenna and feeder (in its bag) including the 817 is just over 3kg… I carry more than that in summer just in water :o)
Have fun building; 80m is the best bet for contacts during the mornings and afternoons 40m can be hard work with QRP levels but occasionally your signals can be very strong when conditions are just right, but that is sometimes part of the fun not knowing just how the propagation is going to be.
Your first 80m SOTA pile-up is going to be interesting :o)
Suitable wire pops up on e-bay from time to time
In reply to G6WRW:
My G6WRW pattern flexweave dipole has been in service for some months and is erected on a 9m pole here at home most of the time. I use it with my FT-101ZD and FC-901 ATU [direct setting]. QSO’s all across Europe and importantly into Scotland on 7MHz. Very broadband tuning. I like it a great deal. I will take it out on activations in 2010 especially when my pal Alastair M6ALR has built his MKARS80 rig.
Today’s question is to do with top band. Advance! and antenna books mention adding loading coils on the far [non-feed] ends of the dipole to get the correct electrical length for 1.85-ish MHz. Anyone tried this?
I’ve searched in vain on the reflector for details of John Earnshaw G4YSS’s syringe mounted loading coils noted in the photos on the main SOTA website. These appear to be acting as a link in the dipole and are very compact and neat.
The list of popular frequencies at Hiking in the mountains: tips for beginner hikers - Mountain Day doesn’t include 160m [probably because it’s used so infrequently hi]. Where in the 1.84 - 2MHz band has SOTA telephony taken place?
One day I’ll complete my VK5JST analyser kit and all this antenna experimentation will get easier.
In reply to 2E0DAI:
Hi David, Top band can be done and has been done from a SOTA summit, yes it is used infrequently on summits as its such a long wave length meaning BIG aerials especially using phone modes at QRP.
Maybe later in the year I will have another play on 160m from a summit as I have a couple of experiments to try out.
I find 1.9mhz - 2.0mhz has the most SSB and sometimes AM activity, Top band is a band i like when i can get on it! Sean M0GIA
In reply to 2E0DAI: My stepped dipole is cut for the top end of the 80M band, with extensions for the cw end, with connectors at the feed-point. Last year I tried joining the ‘fed’ ends (ie, at the apex of the ‘V’) and removing the coax feed. Testing with an MFJ analyser from one end of the resulting long-wire (about 40M of it), with a home-brew pi network antenna tuner, against about 10M of counterpoise earthed with a tent peg at each end, allowed resonance to be achieved across top band. I didn’t go any further because I only has the FT817 available, and much more important, lunch was called. The same set-up did enable every band up to 50MHz to be tuned.
Regards, Dave, M0DFA/G6DTN