[Premium-Rx] MULTICOUPLER IP2

[Sheldon Daitch]

sdaitch at IBB.GOV wrote:

> Kind of a sidebar comment, re antenna multicouplers, when we were still operating the HF receiver site at Greenville VOA, we used a rack of Rohde & Schwarz tube type multicouplers, model unknown, to feed the RCA receivers.  I don't think I have access to any of the manuals, and maybe I can check the R&S catalog at the office on Monday, for the model number.
> (I just checked and the multicoupler was not in the two catalogs I have).
>
> I know they were in the facility in 1979, when I came to work there.
>
> We had one or two transistorized Delta multicouplers, but they had little use, not because they were inferior to the R&S, but going on a 15 year flash back, I think they were just never wired into the RF patch panel in the same manner as the R&S, so most of the time we never thought about using them.
>
> I will have to see what we used in some of our European recevier sites, but bear in mind, most of the antennas were rhombics pointed at the states, so they had some (a lot?) of directivity and somewhat less pickup of European transmitters, perhaps to the point that intermod wasn't a significant problem.
>
> I also don't recall any problems with intermod from the Greenville transmitters, which were about 20-25 miles from the receiver site.
>
> 73
> Sheldon
> WA4MZZ
>
> ----- Original Message -----
> From: k0dan <k0dan at comcast.net>
> Date: Saturday, April 1, 2006 12:08 pm
> Subject: Re: [Premium-Rx] MULTICOUPLER IP2
>
> > "When people connect such a multicoupler to a large wideband
> > antenna, they
> > are in for an unpleasant surprise" depending on their environment.
> >
> > I'm not gonna argue with the and/or comparisons of a $200-$300
> > multicouplerto a 4- or 5-thousand unit, but the facts are that the
> > multicoupler which
> > started this thread (sold, by the way, thanks for the inquiries!)
> > workedFINE. Granted, it was not installed in Europe, at a Voice Of
> > America site,
> > etc., etc.
> >
> > It WAS installed using broadband antennas, in a relatively quiet RF
> > environment (Missouri, USA), and worked FINE. Never encountered
> > intermod,distortion, crosstalk, etc. Sometimes the multicoupler
> > was directly on an
> > antenna, other times it was behind an amateur transceiver's
> > bandpass filter,
> > it worked FINE.
> >
> > The key is to ask the question of what application and environment
> > is a
> > given piece of equipment being used in.
> >
> > To suggest a blanket condemnation of low-end multicouplers (or
> > anything else
> > for that matter) is just stereotyping and generalization. On the
> > other hand,
> > if you're building a multi-receive site which is a 1/2 mile from 100KW
> > transmitters, you have a different scenario.
> >
> > Apples and oranges.
> >
> > Have fun folks...
> >
> > Dan
> >
> >