44ft doublet with folded legs
PA6A in PACC contest
"Stealth DX-ing from your apartment" by PA0FVH
A large metal object of the flat building as vertical antenna.
When it is not possible to erect an antenna, because of restrictions (HOA) or simply because there is no space to do so, you could examine the building for large metal objects, which could be used as an HF antenna. The aluminum fire escape of the flat building for instance is such a large object, which could be used as a vertical antenna. How to bring this thing into resonance? An antenna tuner in the shack was for me out of the question. I didn't want the transmission line (ladder line or coax) to radiate between the tuner and the antenna. On a hamfest I bought the CG-3000 remote automatic antenna tuner and started my experiments to bring the ladder into resonance. The counterpoise consists of 2 radials per band, except for 160m, buried between the tiles on my patio. During my first tests I was driving the ladder directly and with success. To increase performance (RF current distribution over the entire ladder, instead of flowing directly to the brick wall) I have attached a wire in parallel to the ladder and connected this wire to the tuner. The wire is hardly visible on the aluminum cage of the ladder and this makes it a stealthy antenna. I am using this antenna over a year now and the results are very promising. On 80, 40 and 30 meters I have made contacts outside of Europe (in PSK and 40Watts output). On 30 thru 10 meters my magnetic loop is performing better for DX, probably due to a lower take off angle. Fire escape ladder antenna fireescape1.JPG fireescape2.JPG fireescape3.JPG fireescape4.JPG fireescape5.JPG fireescape6.JPG fireescape7.jpg P2150001.JPG P2150002.JPG P2160003.JPG P2160004.JPG P2160005.JPG P4080002s.JPG
- Aluminum fire escape - 10 meters long and 1 meter in diameter.
- 2 radials per band 80m - 10m.
- Remote automatic antenna tuner CG-3000.
- Frequency range tuner and antenna 160m - 6m.
- Wire used: half of zip cord 2.5mm2 stranded silver plated wire with transparent isolation (other half is copper with transparent isolation) used as loudspeaker wire.
- RF choke (2x) coax to shack and 12VDC.
Fire escape ladder antenna