Performance of some antennas

[mentanah]

today i had the opportunity to measure some antennas on a handheld spectrum analyzer from Rhode & Schwarz.
Here i would like to share the results in the pictures:

[MrHoerby]

Die originale ist gar nicht so schlecht, nur ein wenig zu lang.

[OE1MWW]

Even using Rohde & Schwarz, the best of the best, all those measurements depend on the 'counterpoise' of such an antenna.
Peak resonance may shift with the setup. They are all a kind of 1/4 radiator for 70cm and a radiator plus a loading coil for 2m,
so they need metal for the other half side to complete the dipole or ground function. Will be a major difference if the antenna
sits on the UV-K5 or you have it connected via a coax to measure the SWR. Tried to put a choke at 1/4 distance of 2m and 70cm
on the coax. OK, you may see a result, Next I used a small SWR bridge between UV-K5 and antenna - another result...

German saying: "wer misst, der misst Mist. wer viel misst, der misst viel Mist"
(whoever measures, measures crap. If you measure a lot, you measure a lot of crap)

Experiment to do:
Use one of the shown antennas and squeeze a ~50cm wire to the SMA shield on the antenna connector of the UV-K5 and let
the wire hang lose vertical down. Put your UV-K5 on exact the same place on a table, with or without the wire. Compare indicated
signal info on the display of a (not so strong) repeater with or without the wire. You will be surprised ;-)

[mentanah]

That's right. This test is intended to do a relative comparison between the antennas. The setup is kept the same over measurements, with standing analyzer on grounded plane while I stepped back.

Shure if you touch the sma ground nut with a fingertip, the low band drops about 20 MHz and the high band about 50 MHz by increasing the SWR about 1 and 0.5 points.