[BC] processing way back when

[Milton R. Holladay Jr.]

The BA-5 was all audio and took up about two feet of rack space. The one
that used RF was its successor, but I don't know the model #; I only saw one
once, briefly.....
M
----- Original Message ----- 
From: "Robert Orban" <rorban at earthlink.net>
To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
Sent: Tuesday, December 19, 2006 7:50 PM
Subject: Re: [BC] processing way back when


> At 10:03 AM 12/19/2006, Mark Humpfrey wrote:
> >Not the first limiter, but possibly the first "look-ahead" limiter was
> >the General Electric BA-5-A, which is shown in my 1947 GE broadcast
> >audio catalog.
> >
> >According the the catalog blurb, its initial development was done by
> >the CBS technical staff, and it included a delay line in the signal
> >path, to "delay the signal until bias generator circuits have time to
> >reduce the required amplifier gain", and also had a dual-time-constant
> >release "anti-pump" circuit.
>
> When I was working at a summer job at WPAT in 1968, they had one of those
> on their AM TX (an old Federal 5 KW with a separate vault for the mercury
> vapor rectifiers and mod transformer!). The GE had LOTS of tubes. IIRC,
the
> audio was modulated as RF to permit gain control in the RF domain without
> thumps. As far as I know, they also used an RF delay line for the audio. I
> can attest that the unit had good peak control, probably thanks to its
> look-ahead design.
>
> My recollection was that the GE unit sounded good by itself. Later that
> summer, they added a tube-type Audimax to the chain.
>
> The Chief Engineer at the time was Paul DiSavino (sp?) who later left the
> station and started a used broadcast/pro-audio equipment dealership.
>
> Bob Orban