Rounding off a frequency. When I try to enter 771.33125, it gets rounded off to 4 digits which I believe affects the reception.
BCD325P2/BCD996P2: Rounding off a frequency
- Thread starter akafnulnu
- Start date
wtp
Member
no, it does not.
As wtp noted, it doesn't affect reception.. That fifth decimal place is one too many for the scanner to display. It's limited to 4.
wtp
Member
can you go to where it is in the system to see it still shows 5 places out ?
wtp
Member
771.33125
so
771 million cycles per second
331 thousand
250 Hz
so the 5 is 50 Hertz.
i don't know if you can whistle that low.
so
771 million cycles per second
331 thousand
250 Hz
so the 5 is 50 Hertz.
i don't know if you can whistle that low.
I don't know if this would apply to the 325P2. But on many more "legacy" scanners, they also would round off the 4th digit to the right. Except the radio itself wasn't rounding it off. The user thought it was. If you tried to put in for example 459.2125 and the display rounded up to .212 or .213, the radio was actually tuned to .2125.
nd5y
Member
It's only the display that rounds/drops the 5th decimal place, not the receiver.
Ubbe
Member
When I check the exact frequency what my TRX-2 and BCD536 are calibrated to they are 1KHz off in different directions in the 400MHz band.
For the 771.331 frequency one scanner would actually be tuned to 771.129 and the other 771.333
Filters in the scanner are wide enough to handle those kind of frequency issues.
/Ubbe
For the 771.331 frequency one scanner would actually be tuned to 771.129 and the other 771.333
Filters in the scanner are wide enough to handle those kind of frequency issues.
/Ubbe
tvengr
Well Known Member
The 325P2 and 996P2 do not round off the frequency. It only drops the 5th decimal place in the display. If the 4th decimal place shows a 2 or 7, the 5th decimal place is 5.
@tvengr is 100% correct as the P2 series are very capable scanners and simply don’t have the necessary space on the display to show longer frequencies, but they absolutely will save those into memory properly! So, don’t worry, as long as they’re entered correctly, the scanner will save and use them exactly as originally entered.
You MAY be able to see the final digits in ProScan or similar, but I don’t recall if the software will get the list with > four decimal places. I believe it would, but honestly don’t remember. Either way, the scanner is saving it into memory properly.
Lastly, the P2 models use some VERY old code in their firmware that’s carried over from a great many years ago. They simply have added-on and seem to not discard very much. This is why there may be a graphical limitation. One other anomaly that I remember are the four digit system IDs being used with P25 when it’s actually three digits with a leading zero, this is because of being “carried over” from the code used with the older Motorola 3600 systems that did use four digits, something that was simply never updated to be disregarded. I get the “if it’s not broke, don’t fix or change it” outlook with software, but there have been flukes older than a decade that have popped up even in the most recent firmware revisions. The developers probably just don’t have the time to do a complete rewrite, besides the fact that doing so will create a whole new set of bugs. Even messing with too much of the legacy code will likely break something, so there’s an inevitable trade off.
Hopefully, that puts you at ease and details some of the technical side a little bit better.
You MAY be able to see the final digits in ProScan or similar, but I don’t recall if the software will get the list with > four decimal places. I believe it would, but honestly don’t remember. Either way, the scanner is saving it into memory properly.
Lastly, the P2 models use some VERY old code in their firmware that’s carried over from a great many years ago. They simply have added-on and seem to not discard very much. This is why there may be a graphical limitation. One other anomaly that I remember are the four digit system IDs being used with P25 when it’s actually three digits with a leading zero, this is because of being “carried over” from the code used with the older Motorola 3600 systems that did use four digits, something that was simply never updated to be disregarded. I get the “if it’s not broke, don’t fix or change it” outlook with software, but there have been flukes older than a decade that have popped up even in the most recent firmware revisions. The developers probably just don’t have the time to do a complete rewrite, besides the fact that doing so will create a whole new set of bugs. Even messing with too much of the legacy code will likely break something, so there’s an inevitable trade off.
Hopefully, that puts you at ease and details some of the technical side a little bit better.
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