Re: 80m antenna for limited space.
For anyone who is interested in the full set of data:
The first 3 blocks of data are the measured Antenna impedance, Type-26 unun winding impedance, and Type-2 unun winding impedance.
From those impedances I calculated the unun efficiencies shown in the mauve block.
I then used TLD to calculate the coax losses for each unun shown in the grey block.
Finally I calculated the expected net advantage of the Type-2 unun and compared it to the results from the field strength measurements - yellow block.
So, as an example, taking the 20m band data:
Antenna impedance = 1011-j1845
Type-26 winding impedance = 278+j301
Type-2 winding impedance = 585-j3430
Type-26 efficiency = 12.1%
Type-2 efficiency = 82.6%
Type-2 efficiency advantage = +8.3dB
Type-26 coax loss = 1.3dB
Type-2 coax loss = 3.7dB
Type-26 coax loss advantage = +2.4dB
Predicted Type-2 net advantage = +5.9dB
Measured FS advantage = +5.2dB
Reassuringly, the predicted differences in unun performance follow the same trends as the measured differences in field strength.
Steve G3TXQ