Knucker beta testing feedback

[radiogareth]

This afternoon Martin G4FKK and I managed 2 way on 71Mhz 333kS and 500kS one way. I can only raise a clean watt which just scraped through but Martin with up to 5 watts was quick lock and easy copy with audio. Interesting that the path is only showing as 59+15dB on 150W ssb.
My end was Portsdown 4, Pluto at -12, 35dB gain block, 40W mosfet brick amp. (Power showing as 1 watt on my Weltz SP220). Rx was a Knucker 'barefoot' each end, into LFA beams.
Looking good for the weekend
Gareth G4XAT

[Patrice]

Hello
Would it be possible to add a bandwidth of 1.7MHz in the software.
Regards

[g0mjw]

One assumes so, but why? Seems a strange value. Not really narrow band or spectrally efficient. There are no bands the Knucker covers where such a bandwidth would be appropriate.

[g8gtz]

1.7MHz is a standard bandwidth in the HiDES equipment and used in the USA - I think.

I have tested the Knucker receiver with a Hides HV320 transmitter and it works well.

You can set the Portsdown (and presumably Ryde in the future) to whatever bandwidth you want - within the limits that seem to be 25oKHz to 8MHz!

73
Noel - G8GTZ

[G8GKQ]

Hi

As I understand it, 1.7 MHz was only introduced in the DVB-T2 standard, but was back-ported to some DVB-T equipment.

I have just done some testing, and the Portsdown 2020 with a LimeSDR will correctly transmit 1.7 MHz DVB-T. However, there is an error in the current CombiTunerExpress receive software that prevents Portsdown 4 or Ryde receiving it with the Knucker. I now have a corrected version that does work and this will be included in the next Portsdown 4 and Ryde software releases.

Two things to note:

• The CombiTunerExpress receiver with the Knucker tuner is only variable bandwidth below 500 kHz. Above that it only receives at 1, 1.7 (when corrected), 2, 4, 5, 6, 7, and 8 MHz bandwidths.
• You need to amend both the transmit and receive presets in Portsdown to include 1700 kHz if you want to try 1.7 MHz bandwidth.

Dave, G8GKQ

[G1LPS Terry]

Noel Quoted
"You can set the Portsdown (and presumably Ryde in the future) to whatever bandwidth you want - within the limits that seem to be 25oKHz to 8MHz!"

I find that 150khz is the lower limit and its reliable at that bandwidth. 140 and 125khz just wont go. What's the lowest others are seeing ?
picture of M0DTS over 27km on mw's.

IMG_3560.jpg (1.23 MiB) Viewed 13952 times

[radiogareth]

Just a quick test across the shack with PD4 each end (Pluto/Knucker) and its good at 250. Nothing at 125 though but the Pluto is TXing.

Once I found the pages to edit the SR send and RX BW I tried 150 and its good here.

I'll await "more experienced operator" comments as to the feasibility/capability' before messing with the menus any further.

What sort of 'gain' does a drop from 250 to 150 give?

Gareth

[G8GKQ]

Hi Gareth

I've just done some tests as well. 150 works fine from both Portsdown 4/Pluto and Portsdown 2020/Lime. Gain over 250 should theoretically be about 2dB.

Dave

[m1cdq]

I am able to run the knucker and minitioune on the portsdown4 without unplugging and swapping usb leads between the 2.
as i had read you cant have both plugged in at same time.

I've go both hooked up and switching between oscar beacon and bbc tv from belmont