Strange behavior with the 396XT on 6.25k steps

[W2SJW]

Guys,

I just noticed for the first time that the 396XT does not render UHF frequencies that are at 6.25k steps out to the 5th. digit.

I have the ability to hear NYC from where I am in NJ, so I have the FD & EMS channels programmed in my 396 (480 MHz at 6.25k). What I noticed was that Manhattan's fire frequency of 482.10625 got rounded to 482.1062, and when FreeScan read-out the programming, it showed on screen as 482.10620. Is this normal? Is the unit still tuning the frequency correctly?

 

[UPMan]

That digit represents 50 Hz. It isn't unusual for transmitters themselves to be off by more than that under normal operation. You'd never notice any difference in reception from a 50 Hz off-tuned signal.

 

[W2SJW]

Thanks Paul!

 

[cmeese]

173.39625 Rounds to 173.3950

When I manually enter 173.39625 in my 396XT it displays 173.3950, that's 125 Hz not 50 Hz. I'm wondering if that much makes a difference?

 

[pro106import]

When I manually enter 173.39625 in my 396XT it displays 173.3950, that's 125 Hz not 50 Hz. I'm wondering if that much makes a difference?

Did you set the step size for 6.25 in that range (whatever range covers 173 mhz)
By default it is 12.5 which is why it is rounding it off I think

 

[cmeese]

Thanks, pro106import, I hadn't reset the default before your post. I have now and still get the same display; the .39625 rounds to .3950.

 

[cg]

I thought the step in that part of VHF was .0125 MHz changing to .00625 and the base frequencies landed on 172.00000, 173.00000, 174.00000, etc.
If thats the case your example isn't a valid frequency
173.37500
173.38125
173.38750
173.39375
173.40000
173.40625
173.41250

chris

 

[cmeese]

Chris, you may be correct. What I was doing was looking for what frequencies NOVEC (a local power company) operates on. One of its licenses is WFW323 and 173.39625 is listed as one of the frequencies. I wanted to scan it along with the others I found, but noticed when I entered it, the 396XT rounded to a different number. I don’t know if that’s why I haven’t heard anything or maybe they aren’t using it.