PORTSDOWN 4 STOP TX @ 4295 MHz

[HB9IAM]

Condition:
Portsdown 4 - Buster 2023-02-21 firmware 202304300, PLUTO version B and D
Raspberry PI 4 version B ram 4 GB

I get same defect on my 3 Portsdown similar units !

Problem: DVB-S2 Transmission SR 500 H264 source C920 or TEST PATTERN
work correct for 70cm, 23cm, 13cm, 9cm but NO TX at 6cm 5760 MHz
Output spectrum is correct up to 4295 MHz then stop definitively at 4299 MHz

The SIGNAL GENERATOR work perfect up to 5760 MHz !
The LANGSTONE work also up to 5760 MHz !

have no more old firmware to make the same test

Please Help
73 Pierre HB9IAM

[radiogareth]

There is a 'bug' in the 'for the brave' Pluto software that limits DATV to around 4.3 GHz as you have found.
However, DATV Easy WILL work all the way up to 6GHz and although not quite so friendly, ExpressDVB Transmitter will also work.
Gareth

[g0mjw]

It is the limit of a 32 bit unsigned integer.

https://en.wikipedia.org/wiki/4,294,967,295

Mike

[G8GKQ]

The Portsdown uses an rtmp stream input to F5OEO Evariste's Pluto firmware to transmit H264 DVB-S/S2 on the Pluto. Evariste's software has an upper frequency limitation of 4.294967295 GHz (the maximum value of a 32 bit unsigned integer) in this mode. I have discussed this with Evariste, and am waiting for him to fix it.

The Sig Gen and the Langstone both use different ways to control the Pluto so do not suffer from this problem.

Perhaps someone else could look at fixing Evariste's software? There must be someone else with the capability?

Dave, G8GKQ