The problem with LED light bulbs

I had read something to do with electromagnetic interference from LED bulbs in one of the radio magazines but had not given it too much thought. I am in the process of setting up my station and will operate primarily from 144 MHz up, at least initially. My radio room is upstairs in our small house.

I do not have equipment for measuring radio noise. One generally accepts what we have and without specialist gear it is hard to know what the noise floor is on any particular rig. However, the other evening, while I was listening in my vertical collinear with my FT290R in SSB mode, my wife switched on the bathroom lights, and immediately the hiss or hash increased, which would have drowned out a weak signal had I been listening to one.

The bathroom lighting consists of two LED spotlight bulbs. Further experimentation has caused me to realise that there is also an issue with the LED bulb in the radio room.

Naturally I have looked at what alternative might be available. Currently we can still buy halogen bulbs in the UK, but according to the local shop sales person and as apparently confirmed elsewhere, from September 2018 we will not be able to obtain other types than LED.

There is no doubt there is an issue in the general consumer market with interference to DAB radios

My local issue seems mainly to affect 144 MHz with little noticeable interference at 432 MHz, and although I have not looked at every amateur band, in my case there is not any perceivable hash as low as 3.5 MHz, but of course there my noise level is typically S7 anyway.

More on this issue can be found here and it is well worth watching the video by DL9KCE who shows that even a bulb made by a well-known European manufacturer causes a problem at 144 MHz.

We need to launch a campaign although it seems we may be overwhelmed by an inexorable tide to LEDs. What will become of 2 metres weak signal work in an urban environment?

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New SSB/CW dual-band for 4 and 6 meters

Good news. This looks like a great rig. I want…

Ham Radio Blog PD0AC

Still in beta, but might be interesting for the European market. A company called “Noble Radio” (link) is developing a dual-band SSB/CW transceiver for 4 and 6 meters. Price point unknown at this time.

Noble Radio

Preliminary Technical Specifications

Frequency Coverage
4M: 69.9 MHz to 70.5 MHz
6M: 50.0 MHz to 52.0 MHz

Modes:
SSB (USB & LSB) and CW

Circuit Type: Down converting design
Dual Conversion: 1st IF: 10.7 MHz 2nd IF: 25 kHz

Sideband elimination using phasing techniques with digitally generated Quadrature carriers and Image Reject Mixers preceded by 15 kHz crystal roofing filters

Ultimate receiver bandwidth set by adjustable SCAF filters (two 8th order filters used. One for High Cut and one for Low cut)

Sensitivity:
MDS = -130 dbm

Dynamic Range Figures:
Blocking: 110 db
IMD (3rd Order) = 95 db

Selectivity:
500 Hz to 4 kHz adjustable with the SCAF filters
Ultimate attenuation of filters are 55db…

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Planning permission granted for antenna mast

IMG_1031The local council has granted planning permission for my mast. Despite there having been a complaint when I first put up the basic structure on the wall, there was not a single objection to the application. I know the neighbours were consulted by the council because they have told me. Of course, I did speak to all of those I thought had an interest prior to making the application.

As I have previously mentioned, the plan is to have 7 elements LFA Yagi from Innovantennas for 144 MHz, a 13 element from them for 432 MHz, and a 23 element Tonna Yagi for 1296 Mhz.

Within a couple of months, I hope I shall be QRV on those three bands, while at the same time I am thinking about what might be done on 50 MHz and 70 MHz.

SOTA – Homebrew 23cm 12 element Yagi Antenna

Super homebrew work well worth the reblog.

Get out of the Radio Shack and Live Life

Sunday 18 June 2017.  I recently purchased a new 2.5 watt 23 cm transverter from SG-Lab in Sofia Bulgaria. The package includes a 2el HB9VC PCB which has turned out to be a great addition for portable work, particularly from a hilltop with a good uninterrupted view of the horizon.  Today from the summit of Mt Taylor VK1/AC-037 locator QF44MP, I worked Rod VK2TWR in Nimmitabel over 130 km, not bad for 2 watts in to a tiny PCB antenna.

While the PCB antenna is a great addition to the SOTA kit, be it for local summits or perhaps on a long hike 10 km or more, what I really need is an antenna with a fair amount of ‘oomph’ that’s non-techo speak for gain, whilst keeping weight and size or length within reasonable limits.

For SOTA purposes keeping antenna construction as simple as possible is a key attribute to…

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SOTA – Getting on 1296 MHz with a Transverter

I hope to be on 23 cm myself by the end of 2017. Great stuff!

Get out of the Radio Shack and Live Life

How do you get on 23 cm 1296.2 MHz USB for SOTA activations without forking out loads of dough for an ICOM IC-910 or IC-9100?  Answer a lightweight all mode 2.5 watt 23 cm transverter from Hristiyan LZ5HP in Sofia Bulgaria.  The current unit on offer is version 2.3.

SG-Lab all mode 2.5 watt 23 cm Transverter version 2.3.  The parcel arrived after 13 calendar days between Bulgaria and Canberra Australia, pretty good considering the transition points along the way.

The 23cm transverter’s default configuration is simplex with the local oscillator (LO) set to 1152 MHz.  The unit has internal jumpers to change the LO frequency by +/- 2 MHz, this option permits simplex operation on 1294 MHz FM.  A separate jumper configures the unit for simplex or repeater operation while a fourth jumper configures the repeater offset which in VK is 20 MHz.  We don’t have a 23cm repeater…

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Setbacks and progress on the antenna front

IMG_1031

The “offending” mast

Back in January Gary, MM0CUG, visited the QTH to install a mast on the side of our house to support the three antennas I have in mind. For various reasons outside his or my control he was not able to finish the job, so we had the mast up with no antennas.

Gary was scheduled to return to put the antennas on the mast for me, but in the intervening period someone complained to the Planning Department of the local Council. I have spoken to all the obvious neighbours and none has admitted to complaining. I believe all of them, so it is a mystery as to who objected.

One of the planning officers came around, and although many amateurs around here have antennas up without Council approval, I was told that I would have to apply for planning permission, which I have now done. Unfortunately, I must wait up to eight weeks to know whether my application is successful. There is a possibility I will have to take the mast down, although feedback I have received from the Council so far leads me to be cautiously optimistic.

The plan is to have 7 elements LFA Yagi from Innovantennas to 144 MHz, a 13 element from them for 432 MHz, and a 23 element Tonna Yagi for 1296 Mhz. These were the bands on which I was most active over thirty years ago and I hope to make a decent comeback. I am aware that activity is much less than it used to be, but I aim to contribute to a considerable increase.

I just cannot wait to be back doing what I used to. My current restriction to a collinear for 2 metres and 70 cms is very frustrating and I am just not an HF person at heart, though I understand that even if I were, conditions are very poor due to where we are in the Sun’s cycle.

I will be back, by hook or by crook.

How did I get into amateur radio? Part 3

liner-2

Belcom Liner 2

What a sheltered life we led, back when I had just left school and gone out to work. All that discovering girls was a terrible distraction, plus actually having to go to work every day. Well, five days a week and hardly any holidays. I had no time for radio.

However, after nearly five years I started to think about amateur radio, still with top band in mind, and started back on broadcast DX listening. I bought a communications receiver, a Codar CR70A. People eulogise about that radio, but mine was not very good, and I have read about other amateurs / SWLs who were unlucky with their receiver.

I decided to get my RAE and be a thoroughly legal station on the radio. In 1974 I enrolled at Southend College for evening classes leading to the Radio Amateurs Examination, to be taken in May 1975. It was taken by G8GUO, Charlie. He was very good and I learned a lot from him. I have no idea what happened to him as he has disappeared, or changed his call sign, or something.

After a year of taking the train straight from work in London all the way to Southend Victoria, I took the RAE and passed. I have a copy of the May 1975 exam and am amazed how difficult it looks now. There was no multiple choice. We had to answer eight questions; two compulsory questions on licence conditions and six out of eight technical questions, the answers to be written with diagrams. The exam was three hours on the evening of Thursday 15th May 1975. And I passed!

I had thought I would take the Morse test, so waited for a while before applying for a licence. I did not make much progress in that direction, so in January 1976 I got the call sign G8LFJ. This was a Class B licence, two metres and up. I then got an FM rig for two metres with I think eight crystal channels, an IC21A. I put up a ten-element beam and after a while it dawned on me that I had the wrong polarisation for FM. I wanted to work more than eight channels too, so I bought a Belcom Liner 2 SSB VXO rig. This was in June 1977.

The first station I worked on 144 MHz SSB was SM7FJE. I thought this was fantastic. Of course, there was a tropo opening, I did have ten elements for my 10 watts out and (most significant) Bo, SM7FJE near Malmo had an EME array of multiple yagis. Just over an hour later I worked OZ5QF, and that is how I got the VHF DX bug.