Inversion - Beautiful views activating GW/SW-001.

[2E0OMX]

Wanting to try out my new budget HF kit outside of my local stomping ground, I opted to activate Pen Y Fan because it was foggy (I thought there might be a chance of seeing an inversion).

A new car park opened in 2023 - Pont ar Daf. I thought I’d see what it’s like to ascend/descend from there. It’s expensive at £7.50 per day. There was no option to pay for a few hours. It’s only a 5 mile circular from that car park, so you might want to get your money’s worth and extend the route.

Taking the Beacons Way path (at the bottom of the car park) up to the summit, it takes little time to ascend. I’d say that in wet weather, it were better to descend using that path - because descending towards the Story Arms Centre via the Cambrian Way is quite steep, and slippery when wet.

There was little visibility on the way to the top. I found a grassy area ideal for pegging/guying my mast, and a small step ideal for sitting at. I got to work.

Once set up, the sun was trying to break through the mist. I realised I was stood in the middle of a rainbow of sorts… stepping away from it, my radio and logbook were at the end of it - I knew this was going to be a great activation.

After spotting on SOTA watch, I called CQ on 20m. I had 8 QSOs in 7 minutes, including a S2S with @IK2LEY on HB/TI-137.

Next, 10m. 6 QSOs in 5 minutes, including one from the USA.

On 40m, 10 contacts including two unexpected DX QSOs.

I decided to chase a few more S2S contacts, which paid off. @HB9CCZ on HB/BE-118, and @GM5ALX on GM/ES-001 (a 10 pointer!).

Keen to try 2m, I managed 5 more relaxed QSOs. It was nice to speak to other hams and have a conversation, as opposed to the speed dating type of QSOs on HF.

I decided to pack up… then the fog cleared for 5 minutes. The view was spectacular - an inversion just as I’d hoped.

What a fantastic day - thanks for the QSOs, particularly the S2S contacts.

31 QSOs, 13 countries and most importantly a lot of fun.

I did have issues with my audio/modulation. Despite that, I managed a reasonable number of QSOs on different bands. The G106 isn’t that bad - it works… but I really want to figure out the modulation/audio issue on 20m and 10m. Fingers crossed.

[MM0FMF]

@2E0OMX

but I really want to figure out the modulation/audio issue on 20m and 10m

It’s most likely going to be RF feedback. So… you need another HF rig to do the tests.

Connect a dummy load to your rig and then listen to your transmissions on the other rig possibly using headphones. There’ll be enough RF escaping from the dummy load to give a nice signal for the other rig to use. If everything is nice and clean then it’s RF feedback on those bands.

If you don’t have another rig then arrange to do the tests with someone from your local club.

[G5OLD]

@MM0FMF

It’s most likely going to be RF feedback. So… you need another HF rig to do the tests.

That’s a good point Andy !!! @2E0OMX Omar have you choked your end fed like this:

The Xeigu are notorious for RF feedback into the mic. I choke every antenna I use with the Xeigu x6100. There is a thread on the reflector with me moaning about this and trying to fix it on the x6100.

You are welcome to try it with my rig when your next near G/SC-003, if it helps.

And great to work you again today. You were lucky with that inversion ! Nice one !

[GM5ALX]

Great job! Sounds like a fun activation and lovely photo. Thanks for chasing and nice to get a #001 to #001 S2S!

I was in the clouds at the top but it cleared a little on the way down to see some of the scenery. Look forward to more S2Ss with you.

[MM0EFI]

@2E0OMX

was stood in the middle of a rainbow of sorts

A fogbow. I’ve only see one once, and that was on a similar day, with a day long inversion. I have a video of it somewhere, simply called Iversions. A very memorable hike.

[2E0OMX]

@MM0FMF

It’s most likely going to be RF feedback. So… you need another HF rig to do the tests.

Connect a dummy load to your rig and then listen to your transmissions on the other rig possibly using headphones. There’ll be enough RF escaping from the dummy load to give a nice signal for the other rig to use. If everything is nice and clean then it’s RF feedback on those bands.

If you don’t have another rig then arrange to do the tests with someone from your local club.

Thanks Andy - I’ll see who I can play with. Very keen to get to the bottom of it, because I reckon I’m more likely to get contacts if I sound better (particularly chasing).

@G5OLD

The Xeigu are notorious for RF feedback into the mic. I choke every antenna I use with the Xeigu x6100. There is a thread on the reflector with me moaning about this and trying to fix it on the x6100.

You are welcome to try it with my rig when your next near G/SC-003, if it helps.

And great to work you again today. You were lucky with that inversion ! Nice one !

Very kind as always Tim! Thanks for the contact and the encouragement - we spoke on 40m, so you didn’t have the pleasure of hearing my strange double/distorted voice on the other bands.

This is what I’m using, directly into the radio using 4m of BNC to BNC RG58. I’ll certainly try anything that anyone suggests (apart from buying a £1500 radio).

@GM5ALX

Great job! Sounds like a fun activation and lovely photo. Thanks for chasing and nice to get a #001 to #001 S2S!

I was in the clouds at the top but it cleared a little on the way down to see some of the scenery. Look forward to more S2Ss with you.

Thanks Alex - I looked up SOTA Watch and had a go. Perfect timing! Cracking views - looks like you had a great time too. We aren’t blessed with great heights here, but I suppose it makes access to summits easier. The weather’s a bit better too.

@MM0EFI

A fogbow. I’ve only see one once, and that was on a similar day, with a day long inversion. I have a video of it somewhere, simply called Iversions. A very memorable hike.

Thanks Fraser - certainly memorable. I’ve never seen it either - in a way I was distracted by the activation, but I wouldn’t have been up there to see the inversion if I was just out for a hike.

[GM5ALX]

@2E0OMX

This is what I’m using, directly into the radio using 4m of BNC to BNC RG58.

I’d try the coax choke like Tim suggested. With RG58, you’ll need a big torroid to fit the cable (like this one), and of course it’ll end up being shorter - just have to move closer to it! Or get another piece of coax.

[MM0FMF]

I’ll put my “I used to do EMC compliance and approvals” hat on and state:

The issue is most likely going to be RF pickup on the microphone cable. So you need to stop that happening either by decoupling the assorted inputs in the cable, properly screening the cable, choking the cable.

Reducing common mode currents on the antenna feeder is probably a good thing but not necessarily the be-all and end-all of fixes.

[2E0OMX]

@MM0FMF

The issue is most likely going to be RF pickup on the microphone cable. So you need to stop that happening either by decoupling the assorted inputs in the cable, properly screening the cable, choking the cable.

I did wonder about that too - the included mic is a £1 jobby.

I don’t think it’s shielded at all - here’s a pic.

[M0JSB]

Thanks for the great report and photos. Excellent stuff!

@2E0OMX

Once set up, the sun was trying to break through the mist. I realised I was stood in the middle of a rainbow of sorts

It’s not super-clear in this photo, but I remember seeing this small rainbow appearing in the distance in front of me whilst descending from GI/MM-003 last summer. The small dot in the middle of the rainbow appeared to be my shadow as it moved when I did!

[G0AZS]

A classic Brocken Spectre…nice

[M0JSB]

@G0AZS

A classic Brocken Spectre

I’d been wondering if there was a name for this. Thank you!

[2E0OMX]

@M0JSB

I remember seeing this small rainbow appearing in the distance in front of me whilst descending from GI/MM-003 last summer. The small dot in the middle of the rainbow appeared to be my shadow as it moved when I did!

Thank you Matthew. Memories like that make it even better, and it’s great to share.

@G0AZS

A classic Brocken Spectre…nice

Marc - thank you. I just looked it up: Brocken spectre - Wikipedia

Now that we have an official term for it, I wonder whether there’s an opportunity to earn extra activation points… seeing as it’s a memorable phenomenon? (I need all the points I can get).

[M0JSB]

@2E0OMX

Memories like that make it even better, and it’s great to share.

Thanks Omar. One of the many reasons I enjoy reading reports on this reflector is that it takes me back to moments I’ve enjoyed (or sometimes not) on past Sota outings!

Thanks for jogging my memory!

[MM0FMF]

Well my first task would be to replace that cable with a screened one.

[G5OLD]

Having been around the block with these Xiegus… I am pretty sure its…

1. Reflected RF down the ground of the antenna. Usually non-resonant antennas.
2. RF Conducted onto the metal casing of the radio from RF ground.
3. Metal casing of the radio is also the ground for the mic.
4. RF from ground feed directly into the mic…

and Result: a rendition of Kraftwerk’s Autobahn straight from the 1980s…

This is conducted, not radiated interference…

Choke your antenna, using a torrid right at the feed of the radio (see pic below). For RG58 you need the Torrid @GM5ALX suggests. That will solve it.

Other solutions that I tried and that worked:

Choking the whole mic:

Choking just the ground of the mic:

Adding an 100uH inductor to the ground of the mic:

I wanted to try a cap to ground on the mic, but i found a final solution…
Final solution: Just went and bought a KX2… problem permanently solved

This is how i operated before the KX2…

[MM0FMF]

Hmmm… I wouldn’t be giving you a job at my EMC consultancy

Case is grounded is normally something we want.

[2E0OMX]

@G5OLD

a rendition of Kraftwerk’s Autobahn straight from the 1980s…

@G5OLD

Final solution: Just went and bought a KX2

One day, I promise.

I was very impressed with the audio on our outing… plus the screen was actually readable. Perfect for the outdoors.

[G5OLD]

@MM0FMF

Case is grounded is normally something we want.

Yes, but none of the system is actually truly grounded and all i’ve done is isolate the mic from unwanted conducted emissions due to the poor design.

[M6GYU]

Smashing report, I especially loved the photo of the person on the edge (0128) with the cloud as the background.

David