DIY Crossband

[ryanwessels]

I hope this is the right forum to ask this question, the mutual aid division my fire department is in uses an 800Mhz Smartnet system, in the counties around us we have divisions using VHF, UHF etc, is there a was to link a set of VHF, UHF, and 800mhz radios together and allow cross band repeating? So if someone transmits on VHF it is repeated over UHF and 800, and if UHF TX then repeat over VHF and 800 etc.

Any help would be appreciated.

[laxplurr06]

I have set-up two CDM1250's one VHF and one UHF for cross banding on the ham band. I used a cable to link both of the radios, and they work well for cross band. I bought my cable from an ebay seller. Setting this up was as simple as configuring a few settings to the accessory port in the CPS. Although it may not be recommended for public safety use I am sure another member has a more professional way to do this, but it is possible.

Good Luck,

Jeff

[Bill_G]

Crossbanding is not unusual as agencies slowly migrate from one system to another including going from UHF or VHF to a new 800 system. Not everybody's budget is ready to fork out the money needed to replace all their gear after the bigger agency upgrades. So, some crossbanding is normal. You need an 800 mobile on a dedicated talkgroup for every UHF and VHF channel you want "interoperability" on. It needs to be connected to a UHf or VHF mobile through a box that lets you set levels and cross COR over to PTT. You can build the box, or you can use a repeater panel. I've seen both.

[ryanwessels]

Not to sound too dense, the CDM1250 or 1550 look great for the VHF/UHF Side along with a CAT-xxx board however I'm having a hard time finding an 800MHZ smartnet compatible radio that has a cable to go to a CAT board, any ideas?

[Bill_G]

Yep. You got the concept. The CAT series controllers will do. A bit of overkill with a ton of features you won't use, but they'll get the job done. You'll have to find a suitable spare 800 radio somewhere in your agency, and probably have to roll your own cables.

[ryanwessels]

Any other suggestions on cheaper controllers or a compatible model of 800mhz Smartnet radio?

[Bill_G]

You can build an interface yourself (cor, ptt, grd, rx hi, mic hi, plus some pots, resistors, and caps). But, you'll have to work with whatever radios are available to you. Maxtracs and Spectras are history. So, you'll be working with an MCS or newer.