Voice contact on 145.800 Simplex?

A Ham on one of the forums I belong to said he had several QSO's recently with the ISS using 145.800 Simplex. I don't see any mention of this anywhere, only 145.800 downlink and 144.490 uplink. The only simplex I see listed is for SSTV on 145.800. Anyone have information on whether this is valid?


kc0pto – Tue, 2010 – 09 – 28 01:44

possible explanation?

Well .. pardon my ignorance here, but what radio are they using? Perhaps it's a model that features dual receive or something and therefore it actually listens on both frequencies simultaneously, and that could explain some of the reported simplex contacts?

Just a shot in the dark, but this has me curious now...

Submitted by arswk2x on Thu, 2010-09-30 08:35.


Anything is possible but it seems unlikely. The crew uses standard channels for public QSO operations so it seems more likely that the ground station was confused as to what they were reporting.

Submitted by N5VHO on Tue, 2010-09-28 09:33.

fm voice simplex - yes its true !

crew contact has been using SIMPLEX not split. spoke to the colonel on 9/13 on 145.800 SIMPLEX and again on 144.490 SIMPLEX . have qsl cards as proof of simplex ops.

Submitted by w2rtv on Tue, 2010-09-28 12:24.


This surprises me since the ARISS site specifically asks Hams not to use simplex. I personally made a contact with Colonel Wheelock on Saturday (Sept 25, 2010) using 144.490 as the uplink and 145.800 as downlink. Anyone else have feedback or information on this?