You probably already know you need to find tx audio input, squelch gated rx audio output, ptt & COS or TOR.
COS is carrier operated relay & TOR is tone operated relay. Preferably you'll use TOR as the active low output to key the vhf ptt. There's software settings to make these I/O's as you need them. It is necessary to adjust audio levels into & out of each radio. This can be done with series resistors or attenuator pads. Chances are you'll need to use caps to equalize the audio as well. Ideally you'll have a service monitor available to check all this. In lieu of the SM, you can carefully compare between the uhf & vhf sides for best match of tone quality & levels. Wish I had the tech info near me but it's all at work. You might find a way to use the dtmf decoders in each unit along with some type of latching relay to perform your control functions. I'm pretty sure there's I/O for the dtmf decoder available on the accessory jack. --- In Repeater-Builder@yahoogroups.com, "bkcarter33" <[EMAIL PROTECTED]> wrote: > > My local Community Emergency Response Team (CERT) has recently > obtained a UHF repeater (ICOM CY-F221S). > .........snipped....... > I would like to accomplish the following and would love to receive > some guidance from someone who has the knowledge to instruct me: > I would like to set up a cross band link for them from the UHF > repeater, to a VHF radio:> Thanks for any help you could provide me, > .........snipped....... > 73 > > Bryan Carter > KE7GVJ > Kaysville CERT Administration >