RE: [Repeater-Builder] Celwave 5042-1

[Gary Schafer]

I don't know that particular duplexer. The close spacing capability is not
an indication that it is a band pass/band reject or a straight notch type
unit. It could be either.

The difference in the smaller mobile type or smaller rack mount type
duplexers is usually in the insertion loss. The smaller the cavity the
higher the insertion loss will be for a given set of operating parameters.
It is usually not a problem getting enough rejection in the notch but it
comes at the cost of higher insertion loss with the small cavities.

The mobile type duplexers are usually notch only type and the other problem
is that they usually have fixed capacitors in the internal loops that you
can not change. So when you move them any great distance in frequency the
insertion loss ends up even higher than the original spec because you can't
change the loop capacitors.

73
Gary K4FMX


> -----Original Message-----
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of Don Spivey
> Sent: Monday, January 07, 2008 2:51 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Celwave 5042-1
> 
> Has anyone had any experience with a Celwave 5042-1 duplexer?  I've
> very skeptical of any rackmount VHF duplexer although specs on the 6
> can version (this one) shows it capable of 500kc spacing at 100 watts.
> I've seen several of these in recent months and mow I'm getting
> curious. I haven't located tuning instructions either, and some of the
> Celwave mobile duplexers can be a bear to tune, so I've heard. For
> that spacing I would assume this must be a band pass/band reject
> design too...73 & Thanks...N5MZQ....Don
> 
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