Langstone Update 16/10/20

[G8GKQ]

Hi Colin and Martin

I will delete the Langstone/stop command in the Portsdown update that is about to be published.

The reason that I did not see the problem is that one of my Plutos has the old stock v0.30 firmware. This does not respond to a simple reboot command sent by sshpass, because the path is not set for non-shell logins. I have changed the reboot command line in Portsdown to:

Code: Select all

timeout 2 sshpass -p analog ssh -o StrictHostKeyChecking=no root@"$PLUTOIP" 'PATH=/bin:/sbin:/usr/bin:/usr/sbin;reboot'

This sets the path and makes the reboot happen for Plutos with older firmware.

Dave

[g4eml]

Hi Dave,
Thanks, I am pretty sure the stop command is redundant before the run command. And removing it will speed up the startup time. The stop command after Langstone exits is OK and will ensure the pluto reboots before being used by Portsdown.
I will update my reboot command to work with the older firmware.

The run command should cope with a pluto that is doing a reboot but it looks like the iio command I am using to check the pluto is ready sometimes locks up in that case.

Colin

[radiogareth]

Mine is up and running nicely, swapping back and forth fine so long as I wait for the Pluto to boot first.....
Unfortunately I've a new broadband noise source 100MHz-175MHz, s7 on the Pluto rubber duck!! Its making the S meter bar and numbers jump around like they are on speed! This if fine for the S BAR but if the numbers are counting/changing the refresh is too fast. Could a fixed scale of S points be used under the bar, rather like the neat little -10kHz/-20kHz marks on the waterfall?

Onward with the 'final' assembly (is there EVER a final assembly!)

Gareth

[G8GKQ]

Thanks Colin

The Portsdown displays an error message if it can't ping the Pluto before selecting Langstone, so I think that we have most eventualities covered. No doubt someone will prove us wrong!

Just doing final build checks before release. Really impressed with the Pluto 5th harmonic performance, and have added 5th harmonic mode to the Portsdown SigGen.

Dave

[g4eml]

Thanks Dave,

I have updated my stop and start scripts so they should also now be a bit better. I was using iio_info to test if the Pluto was responding but that seems to lock up sometimes. I am now just using ping, which seems to be more reliable.

The Harmonic mixing output is quite good, even on 24GHz it seems to provide a useful test signal. I have designed a 10GHz add-on board based on the W1GHZ transverter design but without the mixer. I am waiting for the PCBs to arrive. If it works it should give a few mW on Tx and a reasonable Rx.

Colin.

[g4eml]

Gareth,

I have tried having a fixed scale for the S-Meter but didn't like it, it didn't look good in the available space.

I have however reduced the update rate of the S Meter Numbers so they should be more stable now.

Some other changes....

Stop and run scripts changed to improve error catching. You probably won't notice any difference.

Spectrum display made taller and waterfall shortened. This allows the spectrum display to show 80dB of dynamic range. Previously it was limited to 50dB. (The Pluto actually has about 73dB of dynamic range) Note:- as a result of this you may need to adjust the 'FFT Ref' setting for each band.

Fixed the missing MONI button when in sat mode.

Colin G4EML

[w0iy]

[quote=G4FKK post_id=25010 time=1603025371

One further observation; My Pluto is modified to take a GPS locked 40MHz and yet I still have to make (slight), adjustments to the RX/TX offsets on Langstone. The Pluto reference is set to 40000000 in Portsdown's sig gen settings menu. Are there other, frequency determining oscillators and/or registers in the Pluto?

All the best and sorry for my earlier notes,

Martin - G4FKK
[/quote]

I'd like to know what you are using for the 40MHz GPSDO based reference. Hopefully not something to complex. The ublox don't output that high, if I recall correctly. I do have a 10MHz GPSDO. Suppose I could double-double.

Thanks,
Barry w0iy

[G4FRE]

generating odd harmonics is much easier than generating even ones. For that reason I inject 50Mhz into my pluto and adjusted the pluto software settings to match. For info see pages 8-18 of the presentation i did last month to the Texans at http://g4fre.com/NTMS_Dec2020.pdf

Dave
G4FRE

I'd like to know what you are using for the 40MHz GPSDO based reference. Hopefully not something to complex. The ublox don't output that high, if I recall correctly. I do have a 10MHz GPSDO. Suppose I could double-double.

Thanks,
Barry w0iy

[g0mjw]

There is a setting to correct the Pluto LO by a few PPM so if you replace it with another and don't reset that correction it will be out. See earlier posts on the topic.

Mike

[g0mjw]

generating odd harmonics is much easier than generating even ones. For that reason I inject 50Mhz into my pluto and adjusted the pluto software settings to match. For info see pages 8-18 of the presentation i did last month to the Texans at http://g4fre.com/NTMS_Dec2020.pdf

Dave
G4FRE

I'd like to know what you are using for the 40MHz GPSDO based reference. Hopefully not something to complex. The ublox don't output that high, if I recall correctly. I do have a 10MHz GPSDO. Suppose I could double-double.

Thanks,
Barry w0iy

I would have thought even harmonics quite easy using a doubler (diode) multiplier. 4 x 10 = 40 so a couple of doublers would work, but do you really need to? Won't the Pluto work with a 10 MHz input?