Category Archives: QRM

POTA – FT8, FT4, SSTV, SSB – UPDATE – 18/3/24 –

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After a very busy week, I had Sunday and getting out with my radio to look forward to. Thankfully the weather was being kind to me, whilst not warm, it wasnt raining as we had plenty of that over night !

Plenty of overnight rain at the QTH

I headed out to Boulderwood with the magloop and 705 and was on the air very quickly. Setup is quick and easy with the magloop and I actually learned a good wait to tune the antenna and get the SWR down quicker.

place hand UNDER feedline when tuning = better and quicker matching

I did run into issues starting out with WSJTX and FT8, the time on my computer was just ever so slightly out, but enough for a time sensitive decode of FT8 not to work correctly. I tried updating the time using the windows time server, to no avail ! I had to manually set the NTP server to rolex.ripe.net, sync the time and I was back in action !

control panel time
set NTP sever to ripe’s

I had 10 QSO’s in digital modes done in under 40 minutes, shifting between FT8 and FT4 on 20m, with POTA hunters chasing me thanks to the POTA app and RBN.

pskreport – 10W, FT8, 20M
PSK Report – 10W, FT4, 20m

Having completed enough contacts to activate the park, I was straight into Telephony and SSB. I went onto 17m, not that was any contests on, but I found it a good band for QRP operation, and sure enough I made two contacts, with EA1EC being a POTA Hunter, proving how using PoTA makes getting contacts that bit easier – when running QRP it all helps !

I jumped onto 20M, which was quite calm for a Sunday, and was able to tune around the band, making a contact with IK0VSY, with a good signal report. 20 meters really was the place to be today, so jumped onto SSTV and the pictures started rolling in from other SSTV users.

I waited my time and started to transmit and I made my first SSTV PoTA contact for 2024 ! I was really chuffed and excited, so big thanks to IK2QIN for the excellent QSO.

SSTV QSO received and uploaded to MAX SSTV by other SSTV receivers (Thanks MAX SSTV website!)

I then span the dial on 20m once more, and made 3 more SSB contacts, it was really great to make the contacts, with IU3EDQ being Portable !, but thanks again to EA2DT and EA4TL for hunting me and making the contact with excellent signal reports, with a 59 from me and a 5-5 for my reception report.

The IC-705 really done me a great service today, and being able to use the the voice repeat mode in conjunction with the ‘massive’ battery power of the ‘ultra max’ battery ensured I wasnt going to run out of power for the radio.

repeat mode and <1.3 SWR
on 20m and good results
repeat mode saved my voice

Sadly some massive QRM came in on frequency, but I was able to shift up and continue making contacts, that is the advantage of 20m over 17m, that it has more space in the band, so shifting isnt a problem. I quickly posted my frequency change on the POTA app and was able to continue making contacts !

QRM on frequency, maybe a new mode I’m not aware of !
the sun did try to come out

As the time approached for me to head to the supermarket to get my essential shopping, i packed up in no time, leaving the bunch and the park as I found it. Bolderwood is such a lovely place to come, its relaxing and gets me ready for the busy week ahead. I had a fantastic time getting out on the radio today.

Big thanks to all the people that made a contact with me today, it really is much appreciated and I really enjoy the amazing hobby that is amateur radio !

thanks for all the contacts !!!

*update 18/3/24*

Would like to say BIG thanks to Alessandro who contacted me with his QSL card, little did I know at the time that IU3EDK/P was up a mountain ! I received a lovely QSL card via email and a link to the activation – how amazing that it was a park-to-mountain activation all on 10W of power !!

Thank you Alessandro ! Please check out the activation from Alessandro here

QSL Card from IE3EDK up a mountain in Italy !

First POTA of 2024 – G-0112 New Forest (again)

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So with new choke packed away and bringing the battery pack, i headed out to Bolderwood in the New Forest, arriving at around 10:15, it was still pretty quiet and I had pick of parking spaces and benches.

bolderwood on New Years Day 2024

I then setup the IC705 with the Toybox antenna and radials, which I found getting the radials out much easier this time. I was able to get the SWR down on 17m to a 1.6~1.7.

SWR less today
radial spread
much easier than yesterday

With the antenna setup I then connected the 705 without the MAT Tuner to start with, having the large battery with me was really good as it support the LC IC705 bag nicely keeping the antenna and bag vertical. I then went about attachign the choke-wound usb cable to the laptop.

Uh oh.. this doesnt look good

As soon as the USB cable was attached, the QRM returned ! I could hear the FT8 stations coming into WSJTX without problem, but again when hitting transmit, the audio disconnected. Whilst the QRM was much reduced, there was no doubt it USB cable and laptop was still effecting the radio. I went ahead and the MAT autotuner, to see if that improve the situation, i.e. would it act as any kind of choke between the radio and antenna.

MAT Tuner working great
could I try a choke here
Will I ever make a contact ?

The introduction of the MAT Tuner had no effect on the QRM, although I could see that with the longer coax between the tuner and antenna, I could potentially try putting chokes on here also. I disconnected the radio and just tried calling CQ on 17m QRP frequency, but to no avail. I could pull in signals and I tried jumping on the back on other QSO’s but think I wasnt getting out at all with the little whip antenna.

So I think whilst I have other options, I will explore those as well, I have always done well with the magloop, and its a great antenna, but the one I really want to try is the UK Antenna 40M EFHW, but currently my SOTA Beams mast is damaged from its first and only outing. I explored the website and was able to order the 3 replacement broken parts, which only cost £17.28 with 1st class postage.

The 40M EFHW UK Antenna – the next one to try when the replacement mast parts arrive…

I will continue experimenting with chokes and the Toybox antenna at the QTH before going back out with it again, I think with enough power, it would work well as a portable antenna, with QRP/10W,its giong to be hard work to get on the air with it…

Until the next time, 73s !

2E0FWE

Final POTA of 2023 – G-0112 New Forest

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So having got everything ready and with the weather, whilst chilly, was ok to go and venture out with the radio. I scheduled on the POTA activation website, and headed off to the New Forest to Bolderwood.

The drive in the Hyundai i10 was fine after its recent service, and was good to stretch its legs on the lively A roads in the area. For a small car its got a decent enough poke to make the journey without issue, as I was just carrying my IC705 and a few drinks.. I did notice I had left my ‘large’ battery behind – so I would be running real QRP from the 705’s internal battery and limited to 5W – still, i was nearer bolderwood than I was home, so pressed on.

radials on the floor
radial connection to toybox
SWR 2:1 without ATU

I de-tangled the the 30 meters of radials, this took me a little while, but nethertheless wasn’t too problematic, the ends of the radials have a nice round terminator which makes de-tangling more a case of pulling the cables thru, rather than unpicking a ‘rats nest’ of wire (plenty of experience with the DX Commander and radials there!!!) I used the rig expert on 17m got the SWR across the band down to 2.1:1, which for a compromise antenna was ok.

FT8 RX 100%
TX = ooops
pulsating TX

I hooked up the laptop via Wfview, Virtual Comport and WSJTX. Signals came in no problem at all, and decodes appearing in WSJTX without issue. I then tried to TX, the SWR measurement was the same as the Rig Expert, but oddly the TX ‘pulsated’ as if it was getting disconnected. I went thru and checked the settings once more, no difference between home and here, only delta was the antenna. I tried the USB cable I had packed away to remove wifi/wfview/audio port as an issue, but the noise level went thru the roof! So I went back to trying to get wfview to work, at least at home on 2M I did get out (suprisngly!).

it was not to be my day to make an activation….

As I continued to try to connect, I checked PSK report on my phone – not a single RX. I could only put this down to the combination of the antenna and using wfview, as with a magloop and 5W on an ipad, I would at least get out, and as other POTA activations showed, worked without issue.

With 0 contacts and a slight piece of rain, i forgo the activation and headed home determinted to find out what I could do to solve my WSJTX TX issue.

TX issues with the 705 and using the Toybox antenna

Once home I searched around youtube and found several useful videos and this one demonstrated exactly the issues I faced when using my USB cable.

USB = QRM

With that I searched around the house, the longest USB cable I had was 2M long, and wouldn’t take many wraps of the toroids I have, so have ordered a 5M USB cable and some cable ties from Amazon, hopefully they will be here tomorrow, then I can try USB with a nice toroid to see if that removes the QRM.

a variety of ham specific toroids

I also thought that I should of tried with the ATU between the radio and antenna, as I think that would of also acted as a ‘common mode’ choke, but will try the USB route first as that looks the most promising solution at the moment.

Until next time (which is hopefully early in the new year) 73’s !

So long VDSL!

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Hi All !

A quick one really slotted between work and uni assignments. The shack is now on fibre-coax to the QTH ! I’ve turned off the BT Router, and this had improved the QRM visibly on the KiwiSDR.

Please see video for a demo.

VDSL Demo

More updates coming soon, have an exam Wednesday, so updates will be a little more frequent after that 🙂

Posted in QRM

Tidying the Shack / QRM

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Good day all ! Making this a quick one as its interspersed with Univserity Assignments and Tidying the shack !

So I have made good progress on building racking and getting things ‘generally in place’ around the shack, its still a right old mess i dont mind saying, but its getting there, and better than it ever was with the old tables.

I had some valuable input from a fellow HAM on my WebSDR that the VDSL interference was plain to see, so after a few years away from Virgin Media, I’m resuming my Internet access from Virgin, once that is in place and all my ‘essentials’ proven to work, I’ll discontinue my IP/VDSL link, hopefully that will reduce the QRM.

QRM Visible via KiwiSDR

I did have a chance to play with the IC705 in the garden this weekend, but results on the portable antennas were slightly disappointing.

results from the ‘toybox’ antenna

I did put on a measured radial for 40m but the nearest resonate frequence was a massive 3kHz away ! If the weather holds up, i’ll try out my buddipole, as for temporary use its worked pretty well, whats more i can configure it for VHF/UHF as well by constructing a JPole, so it might be the best antenna for the IC705 without an additonal outlay on more antennas.

I’m going to be quite busy with a couple more Univeristy Assignments and work-work, but will do my best to keep the blog going !

Until next time, stay safe, 73 !

Alan / 2E0FWE

QRM / Tidying the Shack

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So for the first time in a VERY long time (aka YEARS) I’ve had the luxury of a week off work. During the week I found a USB extender was producing a horrific amount of QRM. The offending item has since been disconnected.

I went on to survey my ‘shack’ and that I had ‘allowed’ QRM to ‘sneak’ back in. I was a bit disappointed in myself to be honest as I had spent allot of time and money on virtually eliminating interference, both man-made and natural when I had my TS690S setup as my only station. I was just not paying attention to what I was putting in the shack.

So to make up for my lack of attention, I wanted to understand why this had come about. Mostly the biggest problem is the ease to just add things in and not test them, only to find out they are ruining a hobby I really love.

QRM Identified via KiwiSDR

Looking around the shack I really noticed how even tho I had moved much of the music equipment out, it was still as not as organised as I would like it. Did I need all these computers ? Do I use them regularly, is my setup optimal in terms of service ? For many of the computers, especially my older mac, i really no longer needed it and many smaller projects have come and past.

I looked around our whole house and many things had changed since we moved here, so maybe it was just as good to take a holistic look and think ‘how can i solve this’. With that I rented some storage space nearby.

Storage space not far from the QTH

I was really able to take a big “bite” out of all the things around the house and no longer using. I wont share the pictures on here as its not strictly radio related, but fair to say I made good use of the space and freed up alot of space around the QTH.

This in turn allowed me to think about back in the shack. How can I get desks/working areas tidy and serviceable. I’ve been using computer tables mostly that dont really have the best storage on them, leading to problems of not putting RF chokes on them and ensuring the QRM was reduced. I put too much trust in the power strip RF filter to think it would fix all my QRM issues – obviously it would not.

First call – Ferrite, lots of it and the right sort. Whilst I have VHF/UHF transceivers, allot of my work is on HF. I researched the best ‘general’ ferrite for HF, and think that FT140-43 will reduce/eliminate the RF from getting in and out of the devices. With that I ordered 40 FT140-43 from Qubits. Now *everything* that is in my shack will at least have these ferrites on the power supply/leads, if not more.

I then looked at the desks. I need them to be serviceable. The power-tray racking helped, but I was still having cable management issues, and as us radio operators know, having loops of wire here and there is a great way to introduce unwanted QRM into the shack.

I ordered these Garage Shelving Unit from Amazon which can be split to make a nice height desk and storage space, reducing the amount of ‘wire tangle’ and allowing me to have small boxes to tidy things away.

I’ve also got Aluminium Foil Tape to cover the working surfaces with to ‘bond’ transceivers to desks. This had worked really well when i done it with my TS690S and having the cables from the transceiver neatly on the metal conductive surface the cables was reduced loops massively.

  • The offending USB extender
  • everthing removed, QRP massively reduced
  • Portable radio great for hunting
QRP Hunting

So I will have a very busy weekend coming up to finish up my ‘week off’ but hopefully a shack that is not only free from QRM, but is also tidy and serviceable. I promise to upload pics 🙂

Stay safe, keep well.

Alan / 2E0FWE

Cables & Connectors !

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So will make this a quick one. I follow Tim (G5TM) on Youtube and he published this video on coax.

G5TM – Coax Cable and Why It is so Important

Long and the short of it is basically is treat your antenna as a ‘unit’, i.e. the antenna itself (wire/beam/loop), the connectors and the coax, and in your budget the antenna system is as crucial as the transceiver.

I also asked my long-term mentor and friend PA2TG his advice – guess what the recommendations of both G5TM and PA2`TG recommending the same coax to me for my needs (HF)!

  • 100m
  • connectors and scissors

With that I have ordered and now received some UltraFlex 10 and connectors from W&S, plus the scissors to help me make a good job of it. There is this excellent video on how to put the connectors on the coax.

How to install M&P Connectors

Having received an email from M0MCX that the “Nebula” will be here any time soon I am naturally very excited to see how it all operates !

https://youtu.be/fojfWvUnc8s

INRAD RX7300 & retain ATU

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Having seen the video on splitting the audio source from the main antenna and using a secondary ‘receive only’ antenna for the MFJ-1028 I thought this was an excelllent idea to deal with the QRM I have.

IC-7300 and RX7300 – no ATU tho

This video gives an excellent example of how to install the RX7300 and all the necessary connections. However, I use an MFJ-993B on 160m although my end-fed antenna is only designed to goto 80m. The internal ATU is good upto SWR of 3.0 approx, so an external ATU becomes essential.

My first ‘issue’ was getting the case off. I read comments that others had suffered this as well, beit from overight screws, or using the wrong screwdriver. I found a screwdriver that worked perfectly, but one screw (speaker screw, top left from the rfront) wouldn’t budge. In the end i relcutantly used a dremel and a small drill bit to remove the screw.

I do not understand why manufactures put screws in so tight. I wasnt happy about using a dremel on such a new piece of equipment.

  • how to route the ATU
  • is the fan an option ?

I looked at the ATU cable and where it could fit. I wasn’t going to cut the case, thats for sure, and whilst i dont use the other sockets at the moment, i may do in the future. It felt like i was gaining one feature, i.e. to tap the RX circuit but had to lose another. The Instructions for the tap kit specify that the ATU cable be tucked away and kept away from the fan. However, this gave me an idea to look at could I route the cable around the fan enclouser and not-tighten the screws quite so much ?

  • electrical tape around the ATU feed wires
  • out of the case via the fan, but not thru it
  • magnifying glasses to the ready
making safe the ATU feed wiring

I carefully fed the ATU wiring around the fan enclousre, not thru it, but between the fan case and the chasiss of the transceiver. I put on electrical tape onto the wire and the chassis to provide a degree of protection to the cable.

  • remove the front most cable
  • attach into the jack
  • mount the tap, in this case loopback fitted
  • route the cabling tidly
  • ATU + Tap available !
ATU+Tap available

I was able to get te ATU cable and the RX Tap out of the casing nicely. The next step was to do some basic testing of the transcevier, firstly without the ATU to ensure receive was working correctly, then to test some low-wattage (WSPR) and then higher (FT8) transmissions.

  • 80m
  • WSPR
  • 40M FT8
testing – transceiver only

I was able to receive WSPR no problem and also transmit and see my transmissions were being received via WSPR.net map. This was on 1W of power. I then proceeded to FT8 on 40m, as this is a popular frequency any time of day with generally good propergation. With 20W I was quickly able to make contacts and confirm my RX tap was working correctly and my TX was working correctly.

  • Attach ATU
  • SWR Readings good
  • Temp and Power good
  • 1:1 via ATU
  • No increase in temp = fan good
Testing ATU + Fan

I attached the external ATU via the power and re-routed the antenna feeds to go via the ATU. I kept the RX tap still in a close loop to ensure my previous setup was working correctly.

I was pleased to see that I was reaching Europe on 80m and low SWR, so the transceiver was working well.

I will monitor the fan on the IC-7300 to ensure the the wire between the PCB and the ATU are not being ‘clipped’ or any other damage. Next step is to fit my receive only antenna and test the phasing/nulling of the MFJ-1026.

Until next time, 73.

2E0FWE

Been busy !

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So apologies for the lack of posts – having passed my Intermediate, I then found myself with quite alot of work/other commitments, but heres a condensed update – i’ll do a lengthier one on each topic at a future date.

Antennas!

Up until recently I have been using a vertical di-pole, namely the DX Commander multibander. Whilst I’m happy with how good this antenna is, part of the hobby is learning and trying out new things ! After reading several very promising reports, I ordered the UK Antennas multiband end fed antenna. This product does deserve a write up of its own, which I will do in due course.

End-fed installation and 80M S.W.R graph

Needless to say, I am amazed at how well this antenna performs. It requires quite an extensive amount of space and I was able to re-use my DX-Commander masts as supports. I had ordered and tried to use Sotabeams, but for extended operation, they just didnt seem as stable and well built as the DX Commander. Good news is that I’ve ordered a DX Commander SOTA edition – looking forward to building and trying that out. The Sotabeams will probably stay in storage until i can go out /P /M and use them as ‘temporary’ mobile antennas.

Weather Sats

Having built and used my own ‘V’ dipole for NOAA and METEOR and was really happy with the results, i went to the next level and ordered a helical antenna for improved reception.

This came from the US and I think is hand built to order by National Antenna Whilst I could build a DIY version, I’m averse to going to large shops unless its essential at the moment, the reviews of this antenna are fantastic.

I setup the antenna and started on my mac to start with, and was impressed with the results, as this is somewhat manual and labour intensive, i then setup a raspberry pi running raspberry-noaa Whilst I looked and tried other installations, this was by the far the simplests and easiest to setup. The combination of an amazing antenna and good programming produced frankly astounding results, including my first ever METEOR-M2 decode – all full automated !

meteor, noaa reception via Raspberry pi and National Antenna

First HF QSOs with 2E – new Digital and Telephony

I was very happy to make a QSO with G7VRD. Having metup via the reddit talkgroup and being ‘local’ in terms of radio, we had never been able to reach each other. With the new installation of the end-fed, I was able to make contact on 80m via firstly WSPR then we tried out a variety of different modes. G7VRD was really great in helping me thru and testing various types, having varying degrees of successes across them.

Contact with G7VRD at last !

I was also able to make contacts for the first time via Telephony. I had a great QSO wtih G8MNY who gave me a very detailed signal report, including play back of how i sounded, which was really useful. The combination of end-fed and additonal power is really helping me more on HF.

Whats Next ?

So i have a couple of other immediate things I want to do and are in progress, probably the most important is getting a receive-only antenna setup to restore use of my MFJ-1026 which performed really well previously.

Here is the video from youtube which shows what I’m aiming for – with VDSL in the UK i’m hoping this will help eliminate the QRM in my urban setting.

excellent example of noise cancelling with IC-7300 and MFJ-1026

Now i can also run a beacon, i want to get my PI-WSPR station going on 40m, so will see if i can get the 40m inverted v dipole up !

Until next time (which will be sooner !) take care, stay safe and 73 !

The ongoing quest to reduce QRM – Mains Filter #2

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*** PLEASE NOTE PHIL’S OBSERVATION OF MY BUILD (FILTER ORIENTATION) BELOW ***

I was using the origninal picture and refrencing off the *EARTH* location post, and not looking at the label (LOAD/LINE) – I have since corrected – afaik no damage done, but good to get right first time if you are using the same filter (FN2030-16-06 FILTER) which has a different layout and orientation to the one used in the slides

*** PLEASE NOTE PHIL’S OBSERVATION OF MY BUILD (FILTER ORIENTATION) BELOW ***

Back in May I built this filter for my shack, which provided suitably good results for the time and effort employed. Further to that post G8KVM (Personal “Bern”) posted a follow up link to an updated filter here.

The main difference to this filter was it contained multiple and updated ferrite types as well as a mains-filter. I was immediatly drawn to the idea of further reducing the QRM into the shack as the first filter provided good results.

I ordered the following parts

PartSourcePrice
Large Fair-Rite core 0431177081: MouserFarnell16.47

1463420,FERRITE CORE, FLAT CABLE, 25MM		Farnell4.98
FN2030-16-06 FILTER, 1 PH, 16A, CHASSIS MOUNTFarnell15.97
CE-TEK  GR17012  IP65 ABS Enclosure – 170x170x75mmFarnell8.79
PRO POWER  PG-11 BLACK  Nylon Cable Gland PG-11 Black – Single Pack, IP68Farnell0.80
Parts Ordered for updated mains filter

I would like to point out that when ordering the mains filter (2030-16-06) the picture on the site is an AC filter. The once I received had DC on it, although the product code was the same.

  • supplied parts
  • using an existing 10Amp plug
  • DC Description on the filter sticker
Components, 10A plug and DC Filter, although same 2030-16-06 name

I was slightly worried about the filter saying DC on it, where this is receiving AC current from the mains supply. Whilst rated for 250V i was not going to take any risks, so setup a test-bed outside, where it was thankfully dry and sunny.

  • apply voltmeter (AC)
  • turn power on, read meter
  • verify earth lead correctly attached to case
voltage testing

I set about by first running an unplugged in extenstion, plugging the filter into that, and setting up my voltmeter to read AC from the output terminals. There is only one earth on the casing.

I then went back in doors turned on the power and no popping/arcing/fusetripping was observed. I then checked the output on the voltmeter, and sure enough it was good 240V AC coming out the filter.

I then proceeded to complete the winding for the ferrites.

The cable i used was SEL 10 m 2.5 mm Twin and Earth Cable. This very good solid copper wire. I did have to put on some Electrical PVC Yellow/Green Earth Sleeving to the earth-copper as this is bare when it comes out the original sleeve. I didn’t want to use my electric drill for the twisting of the wire, so done this by hand. Whilst physically demanding, i felt it provided safer and better results.

I was then able to twist the cable thru the torids as per directions. I was rather happy with the results, as it was quite tough to get the cable thru the torid and space it nicely.

  • filter and torids fitted into the box
  • saftey sticker added
installation and safety sticker

Having tested for electrical continuity via a voltmeter, i then proceeded to test with a simple electric lamp which worked perfectly well. There was no issue with the wiring on the toroids or the filter.

I then disconnected my old filter and connected the new filter.

I was immediately impressed that i was now picking out more receive signals on FT8 and Wefax images were incredibly sharp.

cleaner wefax images

I had 4 consecutive QSO’s which had never happended to be before, so was my first time manging a ‘pile up’ of sorts !

In summary for the time and expense this is a fantastic additon to the shack and makes me confident that in terms of power-line RF and QRM I have done as much as I can in terms of mains-filtering.

Thank you again to GM3SEK fantastic blog posting and G8KVM for pointing me in the right direction to the updated design !

73’s and see you on the airwaves soon hopefully !

— Appendix page update ! 🙂

Following Phil’s comments I powered down everythign and re-opened the filter as its been a little while since I closed it up.

In the picture below, the mains is the cable to the top of the page, this connects to the line filter, then in turn the ferrites connect to the output of the filter. I think I have got this correct based on the source picture !

Source – https://gm3sek.files.wordpress.com/2019/10/capture.jpg – All credits to gm3sek.
Pic of filter following Phil’s observations

Whilst mine isnt as tidy, i think it is correct. Appreciate if you can reply to comment Phil 🙂

Posted in QRM