Memory Display - Frequency Truncation

Nick Shaxted

Using the basic memory channel setting in my Flex-6700, SmartSDR 1.5.1 I notice an error in how it handles frequencies in the shf range. HF and VHF frequency handling appears to be fine, the problem arises when dealing with real radio frequencies ;-).

I suspect the problem may manifest itself with VHF frequencies above 100MHz when inserting down to Hz levels.

Here is a snippet of what is displayed in the Memory Channels for my 3cm memories:-
10m Beacon DL4OGI 28.800.000 OH5TEN ... ... ...
3cm Beacon DL4OGI 10.368.100.000 F1ZAP ... ... ...
3cm Beacon DL4OGI 10.368.100.000 HB9BBD ... ... ...
3cm Beacon DL4OGI 10.368.800.000 PE9GHZ ... ... ...
3cm Beacon DL4OGI 10.369.000.000 ON0GHZ ... ... ...

On the face of it all appears to be fine, except the actual frequencies of the 3cm Beacons have been truncated to the nearest full integer frequency for display. The correct actual frequencies seem to be stored on the 6700 correctly as recalls these memories see the radio tune to the exact frequency.

Therefore what we see is

10m Beacon DL4OGI 28.800.000 OH5TEN ... ... ... Note this is correct

3cm Beacon DL4OGI 10.368.100.000 F1ZAP ... ... ...    should be displayed as 10.368.108.000
3cm Beacon DL4OGI 10.368.100.000 HB9BBD ... ... ... should be displayed as 10.368.064.000
3cm Beacon DL4OGI 10.368.800.000 PE9GHZ ... ... ... should be displayed as 10.368.815.115
3cm Beacon DL4OGI 10.369.000.000 ON0GHZ ... ... ...should be displayed as 10.368.925.000

I assume this type of rounding applies to all frequencies above 1 GHz but have yet to test it.

In summary memory channel frequencies seem to be stored correctly internally, when displayed in the memory channel table they are truncated. I can't work out exactly how the trucation works as it is doesn't appear to be consistent.

To check I loaded FRStack and that also displays the memory channels frequencies in the same truncated way which suggests truncation takes place on the Flex radio side.

regards
Nick dl4ogi

Tim - W4TME

I have entered this problem report into our bug tracker for additional investigation. Thank you for the defect report.

Doug - K3TZR

I observed a similar problem a few months ago. I posted a way to demonstrate the problem but there were no replies to my posting.