Hello:
I am planning to sell or swap for an ALPHA 91B| or similar for my very
rare SSB package.

You will find the first SSB 1922 articles by Carson who got the SSB
patent in 1923.
The very rare 1956.special SSB issue of the PROCEEDINGS OF RADIO
ENGINEERS.
The 1954 book SINGLE SIDEBAND PRINCIPLES AND CIRCUITS by PAPPENFUSS et
al at COLLINS.
The 1995 SINGLE SIDEBAND SYSTEM § CIRCUITS also written by COLLINS
engineers including digital methods.
Plus my very clean and working COLLINS KWM 1 including power supply
and DX adapter.
This is the very first 1957 ham SSB transceiver model that made ham
history as the very first SSB transceiver used in a DX-expedition and
remember the very angry Chrustjew hitting the table with his shoe in
the UN? Because of the American spy plane shot down by the Russians.
It had a KWM-1 aboard! Less than 1500 made and rare.According to a
recent QST article.

73s de "argus"