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Friday, 29 May 2015

Israel on 6M? No way!


Here's a quick video of 4X4DK as received at my QTH on 16th May 2015. He was stronger on 14th May when I worked him.

My QSO is already confirmed in LOTW.

Good, egh?

Thursday, 14 May 2015

They call it the Magic Band....


Been messing about today on 6M. There have been quite a few openings over the past few days due to Sporadic E. This was the sporatic e cloud map from DX Maps earlier today:

The numbers in the boxes represent the MUF (Maximum Usable Frequency). This is the resultant QSO map:

How did I do? I worked a lot of stations in and around Europe, my best being 5B4AAB (Cyprus) and 4X4DK (Israel); both contacts must have been multi-hop Es. You can see the spots for 4X4 and 5B4 on the map above. I was particularly delighted to work 4X4DK as G3OCA was calling him and I was the one that bust the pileup! Ken, as usual, had a spectacularly bad signal that was half a mile off frequency. I was unlucky enough to spend some time with 3OCA when I used to go to the Nunsfield House Amateur Radio Group - he is the most arrogant man I have ever met.

This is my all-time 6M log converted to a map:

I am a member of the UKSMG (UK Six Meter Group), and they run a summer marathon on 6M. Here's the log table (before anyone else uploaded today!):

The only thing that I can guarantee is that I won't stay second for long!

good fun, egh?

*** Update ***

Christian SWL in JN77sn has sent me an Audio file of my transmissions from earlier today, take a listen:

Audio File

Monday, 11 May 2015

It's great to be in the fracas!


Today has been an excellent day for 6M Sporadic E. This was earlier this morning:

And then tonight the band opened again:

If you haven't witnessed a Sporadic E opening on 6M before, here's a quick video of Tony, I2PJA received here in IO93GA (that's 715 miles as the RF flies):

I'm no 6M wizzo but here's my 6M QSOs from my log converted into a map:

Good, egh?

Local conditions.

Saturday, 9 May 2015

The Tigertronics Signalink USB


Following my frustrations with the Yaesu SCU-17 rig interface back here:

and more here:

I've been fiddling today with a Signalink USB interface. This suffers from similar issues to the Yaesu device, but there are a couple of excellent internet resources that help you fix it, here:

and here:

So here is my Signalink half way through the fiddling process:

One of the most important mods in the link above is the replacement of a cap on the board with a 33uF value component. My Signalink already had 33uF onboard so this was left as-is.

What I have done is (documented on the links above), firstly added a 4.7uF capacitor to the power rails for the internal PIC:

I have also removed the 1K resistor feeding the audio circuitry power and fed the supply via 470R and the orange jumper wire you can see. This takes the power from the PIC regulator rather than the dirty USB supply. I have also added 47uF tantalum capacitor to the USB power supply:

That has improved the audio response dramatically and here is what we see post modification:

Now, the Signalink doesn't include an FSK switch to run RTTY, so I have modified the rig -> Signalink cable to bring the FSK keying line to an unused pin on the DIL internal socket, and wired that through a 4N32 opto-isolator to a 9 pin D-type connector I have added to the unit:

This connector can now take a Serial-USB adapter so I can run FSK from the PC.

I've also sold my FT-DX5000 and bought an ICOM IC-9100. I have fitted the optional 3KHz roofing filter and the 23cm module in the radio:

Freddie Cat can't be comfy here, but has been supervising most of the day:

Local conditions.

Thursday, 7 May 2015

Whats going on here then - Part II


Following my musings about the really pants audio bandwidth from the Yaesu SCU-17 back here:

I've found an old external USB soundblaster soundcard thingamabob and hooked it up to my PC with the audio in and out directly to the PKT jack on the FT-DX5000 (the same connector the SCU-17 uses for audio to and from the radio).

Here's the comparison between the two:

So the old battered USB soundcard has a completely flat audio response, the SCU-17 is totally pants. I am rather horrified at the frequency response from this expensive Yaesu unit - I don't think it's even fit for purpose!

What  load of Dingos Kidneys.

Local conditions.

Wednesday, 6 May 2015

What's going on here then?


You may remember I've been dabbling with the WSJT modes using meteor scatter and you also might remember that I have a FT-DX5000 with a SCU-17 rig interface.

I tried using the 5000 for 6M MS the other day and found widely swinging power out during transmit. I've done some simple tests today on the set up and with the radio in TX and using a PC based signal generator I see this power output vs. audio frequency:

Now, I would expect this to be reasonably fat across the audio spectrum - this is far from my expectations! This clearly explains why, on TX in JT6M, the power out of the radio varies so much as the tones change.

It's not much better on RX when receiving noise on the band:

Again, I would expect this to be flat.

So, is there something strange going on in the radio itself in the audio circuits or is this the symptom of a spectacularly pants sound card in the SCU-17?

I wonder.....

More on this will follow.

** UPDATE **

I've drawn some conclusions here:

Odd, egh?

Left a jumper on the desk today:

Local conditions....