Tuesday 19 May 2015

PSK-63 working higher up the audio frequency waterfall

I noticed that when working on the 15m PSK frequency (21.070 MHz) trying to make a contact with a contest station on PSK-63 my station could not be heard. The waterfall showed this station at around 2300 Hz.
After checking out my ALC levels it was noticed that the ALC meter reading was considerably down at the low end despite the audio drive level being high. I went into the Transmit section of DM780 (the  Ham Radio Deluxe module dedicated to audio/digital modes) and turned up the volume.
My station still could not contact the caller.

So I changed the radio frequency to 21.07150 MHz and tuned up again. This time the caller was at around 1KHz on the waterfall so was right in the sweet spot of my rigs audio range. The Transmit drive was reduced back to 30% and I sent out a reply to his CQ.
Rig retuned lowering the apparent waterfall frequency
to around 1000 Hz
BANG - got him straight away with the ALC two points less than the FT-450 colon symbol.

The moral? - Try to work stations at around 750 to 1500 Hz on the waterfall, re-tuning the rig if necessary, and you will put out a better PSK signal especially on higher bandwidth digimodes.


Saturday 16 May 2015

Wouxun KG-UV950P review - Part 9 - The S Meter

Hmm. The rig has a LCD display and part of it is the S meter. I don't know what it is supposed to represent as your guess is as good as mine.
Sometimes the meter can show 9 divisions which, presumably, represents a signal of S9. There isn't any +10 +20 db symbol as there are on many other rigs.
In practice you can see all 9 divisions lit up and hear masses of noise as well as the other station.



Other times you can see all 9 divisions lit up and there be absolutely no noise. Then you can get a 5 division light which is a perfectly readable signal with no noise and then another same reading which is barely discernible.

There is no consistency to it.





The squelch control is no better working in 9 steps. I've found that it is best to set it at maximum 9 to avoid it opening every few seconds when set at 1.

All in all the S meter is a waste of space and the squelch control could do with better calibration,


Friday 15 May 2015

6m openings

Over the past couple of days there have been interesting openings on 6m in the 50.100 to 50.200 MHz SSB segment of the band. At the present time there are many European continental stations that are workable from my QTH in north west England. When using Google Earth in conjunction with the Ham Radio Deluxe logbook module I can see most of the stations I can hear are on the same geographical heading of around 310 degrees.

4 x 6m stations worked in around 10 minutes
all lying on the same direction

These stations varied in signal strength from 53 to 59 and sounded like they were in the same room. I did hear a couple of local stations in Manchester which were a few miles away but in the noise. I think they may have been using vertically polarized antennae whereas mine is horizontal. Therefore on direct path I would appear many decibels down to them. However the continental stations would be being worked on the skywave and polarization didn't appear to be much of an issue to them.

The 6m band is quite fascinating. Sometimes there appears to be nothing and then it can be loaded with many stations.
Soon after writing this the band went quiet again. All in the space of an hour!
My advice is keep your eye on the DX cluster in whatever area of the world you live in for advanced warnings.

Wednesday 13 May 2015

Overdriving the rigs ALC and producing spatter

On data modes it is very easy to overdrive the rig audio input causing the rigs ALC circuit to kick in. The result of this is to cause spatter either side of your actual transmission frequency.

When you see this on a waterfall display it looks like a ghost image of the transmission a few 100 Hz up or down.

The yellow coloured PSK-31 images are the same
transmission. The main one is centred at 1760 Hz and the spatter is around 750Hz

You will then get other hams shouting at you in CAPITAL LETTERS telling you to turn the gain down and look at your ALC meter. You can turn the gain down on your computer by simply decreasing the slider. In DM780 it is the TX slider shown below.

Transmit volume slider on Digital Master 780

ON the Yaesu FT-450D follow what I do - link here
Do yourself a favour and clean up your signal. Other hams with thank you for it.

Thursday 7 May 2015

Monitoring transmissions using a SDR receiver

When using digimodes you have to rely upon another amateur who can tell you if you signal is being over-modulated. Or, as per my previous blog entry, look at the ALC meter on the rig.
Another way of doing it is by using another computer in the shack (everybody has an old one!) and logging onto a Web SDR receiver somewhere on the internet.

There are many now and a quick search on Google reveals where they are.

Install Ham Radio Deluxe onto the old PC and set it in demo mode so you are only controlling a demo radio.
I found a piece of shareware software called Virtual Audio Cable that runs in demo mode.
Download it from here

Install it and launch the Audio Repeater part of it.
Set this to take the output of your audio card and feed it to the Virtual Audio Cable 1 as per this picture


Wednesday 6 May 2015

Wouxun KG-UV950P review - Part 8 - The volume controls

Dual concentric volume controls
are on the right hand side of the control panel

The volume controls, as there are two of them on the KG-UV950P, are appalling. Wouxun seem to have not paid any attention to the criticism that it has received both in the press (RadCOM Sept 2014 and internet forums).
The positioning of the controls are fine. They are dual concentric controls the rear larger one controls the VFO B and the smaller forward one controls VFO A.
The criticism is that it is impossible to fine control the volume especially at low settings.

Let me explain.

  • The controls appear to be rotary encoders with end stops at either end to "feel" like a conventional volume control. There are no click stops like a conventional encoder reinforcing the suggestion.
  • There are 16 steps reflected in the display. When going from Vol 0 to Vol 1 the output to the internal (and external) speakers is quite frankly too high. If you are operating at night time you WILL disturb others.
  • Maximum volume appears to be reached at about Vol 4 or Vol 5. The other settings are unnecessary.

I know this rig is intended to be used inside motor vehicles where the ambient noise is loud anyway but most other manufacturers (that I am aware of) have no issues of giving continuously variable volume settings.

Dear Mr Wouxun,
Please fix the volume control firmware setting as it is annoying and drives this operator mad.

G8YPH

Incidently when you turn the rig to FM RADIO mode (broadcast radio) the volume is at a more acceptable and controllable setting.

Tuesday 5 May 2015

Adjusting ALC on the FT-450D

The ALC meter on the FT-450D is a little confusing. The manual is not much help either. However I think I have worked out how to set the levels with an soundcard connected to the digital data socket on the rear.

Your setting will be different than mine but here is how I set mine.

I am using the DM780 module of Ham Radio Deluxe to operated the digimodes. The output of a cheap sound card is connected to the rig via a dedicated data lead.
  • Set the rig at 35 watts power output
  • set the rig to D TYPE
  • Set this to USER-U and exit
  • Tune the rig up to a digimodes frequency (21.070 MHz for instance) on USB Data
  • Press the F key for more than one second to enter MENU mode
  • Rotate the DSP/SEL knob until D TYPE appears
  • Press the DSP/SEL button