Icom Scanning (F70)

[aaknitt]

We have a number of IC-F70S Analog VHF radios. We have noticed that when scanning, the radio will stop on channels with weak interfering signals (like when near a computer) even though the squelch/audio does not open. This is on channels using carrier squelch (i.e. no CTCSS/DCS tone). Is there a way to eliminate this? It is undesirable to have the radio stopped on a channel without the user knowing it (the user wouldn't know unless they were looking at the display), as they could be unknowingly missing traffic on another channel, thinking that the radio is still scanning when in fact it is stopped on a channel. Any advice or guidance is appreciated.

Andy

 

[ElroyJetson]

You'll need to set the squelch a little bit higher. Enabling user set mode on a function button will allow you to make this adjustment whenever you need to.

The F70 is a good radio, but Icom radios in general aren't quite as resistant to picking up computer interference as, say, Motorola's best radios. Tightening up the squelch is the most practical fix.


Elroy

 

[aaknitt]

Ok, that's what I was afraid of. The part I don't understand is that if it's a squelch issue, why isn't it actually opening up the squelch? There is no audio when this happens, even on carrier squelch channels.

Andy

 

[aaknitt]

Also, does anyone have a good explanation of the "Tight Squelch" and "Tight Squelch Offset" settings? Trying to follow it in the help files and it's just making me mad at poor translators.

Andy

 

[RADIOGUY2002]

It's how it confirgured

It's how it configured, one allows you to have a more adjustable setting via user mode (done threw soft key), while the other one is on a more fixed base threw software instead of soft keys. In most circumstances its just easier to use the set mode and set the threshold higher. In most instances you sql setting should not be that low as then your flooding the control gate in the receiver with ambient noise. I agree with Elroy instructions as I have seen this issue happen and reduce it vastly by changing the threshold setting. I can't say I have not seen the same issue with motorola, it just not as apparent in some models.

 

[jeatock]

In "Memory CH, Zone X" each channel has a "SQL Tight" ON/OFF column. Turn the problem channels ON. I usually turn CS channels ON, and leave RX CTCSS channels OFF..
In "COMMON", "SET MODE" "SQL LEVEL" I start with 125 to 150. (The default is 0.) This is the only value the user can change without cloning software.
In "COMMON" "COMMON" the last entry is "SQL Tight Offset" I change it to 35. (The default is 255)

As the radio scans each channel, it looks at the default setting, and if "Tight" is on, adds the Offset Value- simple addition. 125 plus 255 equals 380- pretty deaf. 125 plus 35 equals 160, which is about right for channels that don't use CTCSS.

You will have to trial and error to find settings that work in your environment.

Also, under "SCAN SETTING" "TIMER" "StopA, StopB, Resume" I have found 3, 2, 1 works best for normal operation.

Icom scanning is slow and deliberate by plan. Don't scan 50 channels or you will miss the important stuff. Don't change the Fast/Slow times or you will end up not decoding CTCSS or tones properly. Also remember that 2-tone signaling is L-O-N-G and requires that 0.6 of the A tone and 1.0 of the B Tone be decoded with no priority scan break in the middle. We use 5-tone PMR because its much more dependable, and allows for ANI and other functionality.