Kevin,
Yes, it is asymmetrical. Each of the three high-pass resonators has two
black plastic plugs near the connector end, while the low-pass
resonators each have one plastic plug. A Celwave engineer told me that
the 5085-1 is manufactured to order, and that the coupling loops are
factory-adjusted through these ports for optimum return loss at a
particular split, and for a certain band segment. As a result, the
5085-1 is not really tunable over the entire high VHF band. I don't see
that as a negative, since it was ordered specifically for this portable
repeater application and is not likely to require retuning.
73, Eric Lemmon WB6FLY
Kevin Custer wrote:
>
> Eric Lemmon wrote:
>
> >It comprises six helical resonators in a notch-only configuration. Its
> >insertion loss at RX is 1.1 dB, and at TX is 1.4 dB. The notch depth at RX
> >is 92.5 dB and at TX is 79.4 dB. These are very good numbers, better than
> >what is needed for
> >zero desense in this application, and are roughly equivalent to four 8 inch
> >standard cavities at a 600 kHz split.
> >
>
> Is it asymmetrical in design or what is the reason for the differing
> numbers between the two sides? At least the notch of the transmitter
> side-band noise is the big number.
>
> Kevin
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