BCD996T Major modification

[triryche]

Hello All,

Just a thought here and I am wondering why this hasn't been a manufactured option yet like it is on ham and commercial radios..

Why not multiple antenna ports on the top of the line scanners? My wish at minimum would be a seperate antenna port for 800 MHz so I could use a nice 5 or 7 dB gain antenna for that and a high gain VHF/UHF antenna for others. I'm sure the radio could have a menu option for configuration so that one could still use just one port but I for one am tired of trying to find a mobile antenna that gives me satisfaction accross the board and in the home shack as well. Sure there are antennas out there that will give adequate coverage but I'm one that can't stop at "ok" and always shoot for the best! :wink:

Something tells me this is not a mod that could be done to existing units but I thought I would throw this out there just in case the possibility is out there or has already been done.

Happy scanning!

 

[n2mdk]

This may not be the answer you want but why not buy a diplexer, yes it's external but that's what you would be doing internally if it could be done.

 

[triryche]

But is there such a duplexer that just seperates 800 MHz from other bands?

 

[n2mdk]

Yes they do companies like Tin Lee make them, they will build custom ones http://www.tinlee.com/index.php
There are numerous threads on the subject like these
http://www.radioreference.com/forums/showthread.php?t=104064 http://www.radioreference.com/forums/showthread.php?t=56526

 

[triryche]

Beautiful! Thank you. I did a search of the forums here for duplexers and that one did not come up or I missed it. Thanks again, I appreciate the response.

 

[n2mdk]

Search using diplexers, I know they get called duplexers but that's not technically correct.

 

[af5rn]

I'm not sure a diplexer would work any better in a receiver than a simple combiner, so long as you are utilising antennae of different bands. And combiners are uber cheap.

But the reason they don't do it is because those who would want to run separate antennae are in a SERIOUS minority. It is not sound business practice to engineer your products for the minority of your customers. Especially when a fifteen buck combiner will solve that minority's problem. That would leave over ninety-five percent of your customers wondering wtf you were thinking by putting separate antenna ports on a multiband scanner.

 

[triryche]

I've tried your basic "T" combiner and also used a Stridsberg non-amplified multicoupler and in both cases the VHF band becomes greatly attenuated while improvement on 800 was only slightly noticeable. In the base set-up I tried the same thing using an 800 MHz 9 element yagi and a 155/455 dual band high gain vertical and this worked well for 800 MHz but on the VHF band I had FM radio broadcast overload accross the band on any radio. Upon disconnection of the 800 Yagi, the FM went away.