[ARC5] Radios and the Canal

[mstangelo at comcast.net]

I worked for ITT world Communications and toured the WSL site in Southhampton NY before in shut down in the late 1970's.

One of the circuits we administered was one of the last, if not the last, commercial point-to-point HF circuits. It was a UN to Havana diplomatic circuit.

All other international circuits migrated to cable or satellite but the Cuban's did not want to move.

It was an FSK circuit. Diversity reception equipment was located at WSL and included two Hammarlund SP-600 receivers and a Northern Radio Master Oscillator.
The operator mentioned to me that the Hammarlund's were prone to drift and external oscillaotrs were required for FSK circuits.

Mike N2MS


----- Original Message -----
From: KA1KAQ Todd <ka1kaq at gmail.com>
To: Mike Everette <radiocompass at yahoo.com>
Cc: ARC-5 Mail List <Arc5 at mailman.qth.net>
Sent: Fri, 17 May 2013 13:58:37 -0000 (UTC)
Subject: Re: [ARC5] Radios and the Canal

On Fri, May 17, 2013 at 7:46 AM, Mike Everette <radiocompass at yahoo.com>wrote:

> Hammarlund built a very fine radio indeed, except for one thing...
> trademark drift.  It seemed the same in the HQ-120-X, HQ-129-X, BC-779,
> BC-794, HQ-150, HQ-170 and HQ-180... I've used them all.  Oddly enough, the
> HQ-180 doesn't appear to be as pronounced as the 170 for some reason.
>

A trademark that appears to be exclusive to amateur operators, apparently.
Can't speak to all of the lesser models Mike, have only used the 120 and
150, both of which seemed quite stable after a reasonable warm up period. I
do know that the Super Pro line was very clear in their manuals that the
receivers were meant to be left on to stabilize. All that mass wasn't meant
to be switched on and off on a whim like the old kitchen AA5. Use them as
intended and keep them in fighting trim, they're tough to beat by any
standard. Military and commercial ops seem to have done quite well with
them.

<snip>