Batboard

Which is the most popular deviation used on 900? I hear a lot about using GTX's with no hardware modifications which means 2.5 KHz. I also hear about using 800 Maxtracs which, if used with the existing IF filters, means 5 KHz. The few 900 repeaters I actually know anything about all use 5 KHz. I was thinking it would be easier if most folks are going to use radios without hardware mods to use 2.5 KHz. I am working on a repeater using GE EDACS gear which will be 2.5 KHz. Of course, most radios meant for 2.5 KHz on transmit will easily do 5 KHz. Likewise a receiver with IF filters for 5 KHz will work with 2.5 KHz deviation. The only real problem comes when trying to use a receiver meant for 2.5 KHz on a system set up for 5 KHz. What does everyone else use?
Thanks

Most hams I have spoken to, say that unless the system you want to use is 5kc, leave the radio alone at 2.5kc.

2.5kc is the only way to go.


David Epley, N9CZV
Show Low, Az

90 % of the equipment is 2.5khz dev, if you try to go wide you will have a problem with the reciever pass band.
and you will also cut the no# of available channals in half!
jim
ka3idn

Then there are those that try to compromise at 3.0 to 3.3 Kc. Totally unacceptable. The standard is 2.5 and it works well.

73 Tom KB5DPE

I found that several GTX portables were actually coming up with about 1.75 kHz deviation, so I bumped them up to about 2.6 kHz with DPL. Our local repeater is also using a MaxTrac as a receiver and no one is close enough to use these radios on a simplex channel, so this slight compromise helps those operators who just don't talk loud enough.

My GTX mobile was also underdeviating when I got it, so it too was adjusted higher.

Lest you think my equipment is at fault, I checked the deviation with my recently calibrated signal generator and spectrum analyzer and everything seems to agree within 5%.

Bob M.