4m band activation?

[ke9ns]

In PowerSDR ke9ns v2.8.0.300 I have activated possible transmit on the 4m band (70mhz) for the Flex-5000

In experimenting with the VU5K module (extending the Receive range of 2m and 70cm), it appeared that the Upper Receive limit on the Flex-5000 was possibly 75mhz? I assume this is really pushing it as the code itself has a 65mhz upper limit. The Flex-1500 has a 54mhz upper limit

But the radio does not have a 4m LPF, so you would need an external 4m LPF (Like the external LPF I use for 630m operation).
And the radio has no calibrations for 4m transmit, and so uses the 6m calibrations.

For those with authorization To transmit on 8m, you will need to "Extend" or "Mars" the radio CTRL+SHIFT+D, Low Level Hardware tab, select Mars.

Please let me know if you are able to use this band successfully (both Receive and Transmit)?

[ke9ns]

Update: Transmitting on my Flex-5000 into a Dummy load, and using my SDRPlay RSP1A Receiver appears to confirm that 4m transmits.
However... When you first PTT, you can see harmonics across the Panadapter, but then the signal instantly gets better, but you can still see a little bit of a upper and lower harmonic from the center. Voice appeared to transmit clean and clear.

It seems that the Flex-5000 transmits clean up to around 65mhz before harmonics appear, and of course it lacks a LPF for 4m.
I was surprised it works at all above 65mhz.

Darrin