145.7MHz DVBT will not work for transverter use

[arthur21]

I have been setting up a 6m DVBT set up using a Microwave Modules 2m to 6m transverter and in order to tx on 51.7 I need to input 145.7MHz and have discovered neither my Portsdown 4 or 2020 will produce a DVBT signal below 145.85MHz thus putting my 6m signal on 51.85 is changing the transverter xtal my only option
73 Arthur
G4CPE

[G8GKQ]

Hi Arthur

I tested this Portsdown 4 - LimeSDR - Attenuator - Knucker - Portsdown 4 and it worked perfectly. However, you are obviously using a Pluto which, as you say, does not seem to work below 145.85 MHz. A surprise to me and very strange!

I'll look at this over the next few days but, in the short term, do you have a LimeSDR Mini that you can use instead?

Dave

[arthur21]

Hi Dave
Thanks for your rapid reply. I was testing with Portsdown 4 with Pluto and the 2020 with a Lime mini.
I have followed you suggestion and connected the Lime to the Portsdown 4 and that works fine so problem solved.
Tomorrow afternoon I will be testing 6m DVBT with Graham G3VZV and now on 51.70.

73 Arthur
G4CPE

[G8GKQ]

Excellent Arthur

Pleased to hear about the planned 51.7 MHz activity.

I'll let you know when I manage to cure the problem....

Dave

[g8gtz]

Interesting - I just tried my P'down 4 (latest dev version) > Pluto running DVB-T and it does transmit on 144MHz....

73
Noel

[g0mjw]

It sounds like the Pluto range is constrained in some way, perhaps in the firmware or the control. I was testing DVB-T on 149.5 MHz at the weekend. This is transverted to 29.5MHz. However I was using a LimeSDR. So that tends to confirm the issue is not in the Portsdown front end but how it drives the Pluto and what constraints are set.

Mike

[G4GUO]

I have just tried the Pluto with DATV-Express and that works fine on 145 MHz.
I believe the issue maybe to do with the firmware version on the Pluto.
I am running v 0.31 the latest however is v 0.33. Analog Devices seemed to
have nobbled the extended frequency range in their latest firmware.
There is a mention of it here
https://forum.amsat-dl.org/index.php?th ... ware-0-32/

Hope that fixes the problem.

- Charles

[g8gtz]

Hi

I am running F5OEO "for the brave" firmware as per the BATC wiki when using the Pluto for DVB-S with the Portsdown.

Available from the wiki here: https://wiki.batc.org.uk/File:FIRM2101RC.zip

73

Noel

PS I found this on the web:

Starting with PlutoSDR firmware revision v0.32 an additional variable should be set after the other commands to enable frequency extension to work:

# fw_setenv compatible ad9364

[g0mjw]

I have just tried the Pluto with DATV-Express and that works fine on 145 MHz.
I believe the issue maybe to do with the firmware version on the Pluto.
I am running v 0.31 the latest however is v 0.33. Analog Devices seemed to
have nobbled the extended frequency range in their latest firmware.
There is a mention of it here
https://forum.amsat-dl.org/index.php?th ... ware-0-32/

Hope that fixes the problem.

- Charles

I considered that but it would not work at 146.5 MHz without the hack? Unless there is a 146 MHz limit in the new firmware.

[G4GUO]

I considered that but it would not work at 146.5 MHz without the hack? Unless there is a 146 MHz limit in the new firmware.]

The hack doesn't work on the new firmware