BATC Forum

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

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

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.

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

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

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.

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

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

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