Adam,
Although the preselector is manufactured by RFS/Celwave, HFD8461A is a
Motorola part number. This preselector is intended to be used in the
GR1225 and similar repeaters in the 144-160 MHz band. It appears to be
similar to a Celwave 911-PB4-1-2 unit, except that it has N connectors.
It may be a unique design for Motorola, and not available as a Celwave
product line item.
I looked in my GR1225 and RKR1225 manuals for additional information,
but found none. Most such preselectors are bandpass versions of mobile
notch duplexers, with all resonators in series. You should be able to
simply rough-tune the preselector on a spectrum analyzer for a peak
response at the receive frequency. Then, install it in your receiver
feedline and fine-tune it with a service monitor for best sensitivity at
12dB SINAD. Be aware that helical resonator preselectors are rather
lossy, with insertion losses between 2 and 4 dB.
Try calling Motorola Parts ID at 800-422-4210, and ask for the
publication number that covers HFD8461A.
73, Eric Lemmon WB6FLY
"Adam T. Cately" wrote:
>
> Looking for tuning instructions and/or information on a Celwave
> model HFD8461A preselector-thingy-do-bob - any help would be appreciated.
> Direct replies are encouraged. Thanks.
>
> - Adam -
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/
<*> To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
