Icom 718 Band Indicator not chagning with Frequency

[KB1TJY]

I apologize if this is not the correct category in the Forum but I could not find on for Transceivers.

I have an Icom-718 which in the past would change the Band indicator when the frequency was input. I.e., if set for 7.200 and 'LSB' was displaying, changing the frequency to 14.250 would change the band indicator to USB.



This is no longer happening. If I move from 7.200 to 14.250, "LSB" is still displayed. Rather, I have to manually push the Mode button. I've reset the CPU - no change.



Any thoughts as to what is going on?



73's,


Lyman

[KO6WB]

According to the manual the last frequency used and the last mode of operation used is stored in the Band Stacking Register. Try selecting the other bands like 17m, 15m, 12m and 10m and see if they still have the USB mode selected. See if you can select a different mode for these bands and then go to the 40m band and see if you have the LSB mode selected. Now return to the 20, 17, 15 12 and 10 meter bands and see if they retained the mode selection. If they switched to LSB then the Band Stacking Register is bad. If you can select USB for any of the bands and then leave those bands and upon returning to those bands the mode has switched to something other then what you selected, then the Band Stacking Register is not doing it's job. The location of this register is a mystery and probably located in the EEPROM but I'm not certain of this. The service manual was no help in this regard. It seems like your only option is to contact ICOM. Their reply to any question you have is always "Send it in". So if this is a problem that really bugs you then a repair at ICOM is in order unless my guess of the EEPROM is correct. Then all you have to do is replace that. As I have indicated I am uncertain that is where that information is being kept.
Hope this helps
73
Gary

[KE3WD]

I apologize if this is not the correct category in the Forum but I could not find on for Transceivers.

I have an Icom-718 which in the past would change the Band indicator when the frequency was input. I.e., if set for 7.200 and 'LSB' was displaying, changing the frequency to 14.250 would change the band indicator to USB.



This is no longer happening. If I move from 7.200 to 14.250, "LSB" is still displayed. Rather, I have to manually push the Mode button. I've reset the CPU - no change.



Any thoughts as to what is going on?



73's,


Lyman

Don't know for certain with the '718, but things like this are often the case when a rig has been modded to transmit out of band...

[KB1TJY]

According to the manual the last frequency used and the last mode of operation used is stored in the Band Stacking Register. Try selecting the other bands like 17m, 15m, 12m and 10m and see if they still have the USB mode selected. See if you can select a different mode for these bands and then go to the 40m band and see if you have the LSB mode selected. Now return to the 20, 17, 15 12 and 10 meter bands and see if they retained the mode selection. If they switched to LSB then the Band Stacking Register is bad. If you can select USB for any of the bands and then leave those bands and upon returning to those bands the mode has switched to something other then what you selected, then the Band Stacking Register is not doing it's job. The location of this register is a mystery and probably located in the EEPROM but I'm not certain of this. The service manual was no help in this regard. It seems like your only option is to contact ICOM. Their reply to any question you have is always "Send it in". So if this is a problem that really bugs you then a repair at ICOM is in order unless my guess of the EEPROM is correct. Then all you have to do is replace that. As I have indicated I am uncertain that is where that information is being kept.
Hope this helps
73
Gary

Thank you, Gary. It did retain the proper mode so it looks like this is okay. I did call Icom and they said, as did you, that the last frequency used and the last mode of operation used is stored in the Band Stacking Register. I would have bet my life on it changing to the proper mode automatically when going from, as an example, 10M to 40M but apparently this is just not the case. Thank you for taking the time to go through the service manual, much appreciated!

73's,

Lyman
KB1TJY

[KB1TJY]

Don't know for certain with the '718, but things like this are often the case when a rig has been modded to transmit out of band...

Thanks. Nope, haven't made any mods to the unit....yet :-)