BATC Forum

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

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

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

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

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

73
Noel

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

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

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

G4GUO wrote: ↑

Thu Jul 01, 2021 7:10 am

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.

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