Flex 6500 10MHz reference input indication

tom_m0lte

I am looking for an indication that my Flex 6500 is using the 10MHz reference input signal I am applying to the rear panel port.

I contacted support today who have responded to state that there is no way of showing this in SmartSDR, nor can one be added, owing to hardware design.

Is this truly the case? Does anyone have any bright ideas as to how to verify which reference it is using?

KD0RC

Hi Tom, Go to Settings, Radio Setup... and select the RX tab:

This will show you whether your 10 MHz frequency reference is in control.

tom_m0lte

> @KD0RC said:
> Hi Tom, Go to Settings, Radio Setup... and select the RX tab:
> This will show you whether your 10 MHz frequency reference is in control.

Hey Len, thanks for this. If only...

Fine on the 6400 and 6600, but not the 6500. See screenshot.

KD0RC

Hi Tom, what version of SmartSDR are you running?

tom_m0lte

3.4.24 here.

tom_m0lte

Same on 3.5.9 too.

KD0RC

Ah, OK. I didn't realize that the earlier 6000 rigs were different in this respect.

I suppose that one way to test it is to disconnect the 10 MHz reference and run the calibration (click the Start button) and see what number it puts in the offset field. It looks like you are in the UK, so you will need to use a Cal Frequency that you can hear well there. It needn't be 10 MHz. I live very close to WWV, so I use 2.5 MHz.

Next, reconnect the reference and run the calibration again. If it puts a very low number in the offset, you will know that the reference is working properly with the 6500. Mine typically comes up with an offset of 4 or 5. I normally just set it to 0.

tom_m0lte

Thanks- I’m not sure what station I can use as a reference here in the UK, but I’ll have a look.

Perhaps I could just connect a short wire to my GPS DO 10MHz output and wave it near the Flex 😄

KD0RC

Indeed, you could!

There is also a signal from Spain that might work:

I am sure the oddball frequency is to keep it from being zero beat with WWV here in Colorado.

dxinfocentre.com/time.htm

WX7Y

The 6300, 6500 and 6700 DO NOT show what the GPS is doing like the 6400 and 6600 do so the only way to tell is to Click on the "Start" button and if it is using the 10Mhz from external GPS then your frequency will be really close to 0, Here mine shows +10 ppb high, If your external GPS is not working then this number will be more then +-1000 Usually much higher than 1K ppb using the internal radio clock.

Unplug your External GPS and run Start again to see the difference, It is also quite common for this to drift a little +-.

I'm also pretty sure this uses the Regular Antenna port to sink with your Local time HF Broadcast, the 10Mhz input is NOT for an Antenna to receive a 10Mhz signal but a GPS local source plugged direct into the Radio

Hope this helps and clears up any confusion.