LQQking at the antenna on his Pro-106, I would say that it is the RS # 200-0006 telescoping antenna
that many feel improve HF,VHF and Air/Mil-Air reception. I prefer the RS #200-0283 800 Mhz antenna
which improves the 700/800/900 Mhz trunking systems I monitor and I like it's more practical size aspects.
Pro-2067, 2055, 2052, 2017, BCD-996T
Grundig YB-400PE, Radio Shack DX-396
RS 20-043, 20-073 ST2, 20-176, 20-283's