AmateurRadio.com

It was time to upgrade the interior lights in my 2004 Volvo. I got some lamps from Ebay specified as LED Festoon, 80-85lm, 12V. As many others have experienced they kept on glowing faintly after the door was closed. When the ignition was turned off the lamps were completely off also, so there was no danger of draining the battery. Still it is not the way one expects lamps to behave.

One can get more expensive LED lamps which avoid this faint glow, “Canbus error free” seems to be the way to specify this. But mine were of the plain type, and the problem seems to be the leakage current in the FET switches that turn the lights on and off.

All it takes to solve it is a parallel resistor. Some have used 1k, others larger values. I just made some trials and found that 10k worked well. The advantage is that 10k will only dissipate 18 mW @13.5 Volts, while the 1k will dissipate ten times that, so I could use a small 1/4 W type. I soldered it on the back of the board as the image shows.

The reason for switching to LED is not really to save energy as the savings aren’t that great anyway. The whiter and brighter light is more important as you can see in the image with the LED to the left and the old incandescent lamp to the right.

While at it, I just had to do some reverse engineering of the LED lamps. There seems to be four parallel groups of three series-connected LEDs (the three in a row) giving a forward voltage of about 8.3 V. They are driven via a resistor of 120 ohms in series with what seems to be a bridge rectifier since the lamps don’t depend on being connected in a particular way with respect to polarity. They draw 18 mA @ 12V and 28 mA @ 13.5 V. This is not a very fancy way of constructing a LED lamp as there is no constant current regulation. The intensity will therefore vary with voltage, but hopefully it will work well here.

Sverre Holm, LA3ZA, is a regular contributor to AmateurRadio.com and writes from Norway. Contact him at [email protected].

It's time for some surgery.

I contacted Elecraft to see what upgrades were available for my K3 and since my rig is not the 100 watt model it eliminated some upgrades. I have already done some modification upgrades to my rig already. There sure is something to be said for opening up your rig and waving a hot soldering iron over it for the first time. I will admit I never get used to the modifications that involve soldering. The next upgrade for my rig was replacing P30 and P35 which are headers. The new headers are gold plated and transfer data from the radio's brain to the rest of the rig. The new gold headers are more reliable and all new K3's are being shipped with these. P30 is a small 5 pin header but P35 is a 30 pin header! Before undertaking this task you need to have the "right" tools for the job. I am a firm believer that the right tools can be the difference between success and and the "oh my god" results. In this first post I'm going over the equipment I will be using.
First off an anti static mat with a wrist strap, when dealing with state of the art radios this is a must! A medium quality soldering station makes your soldering jobs a pleasure. I have the WellerWES51, this is a nice temperature controled unit. The tips can be changed out for varied soldering jobs and what's nice with this grade of soldering stations the tips heat up very fast and stay hot.
A soldering station would not be complete without some solder. I have in the past built the Elecraft KX1, 2 Elecraft K2's and at least 25 or more other projects having to do with ham radio. The solder I use is what's called SN63PB37. So what does this mean..........it's make up is 63% tin and 37% lead. This solder flows well and does not take real high temps to get it flowing. For the job at hand with my K3 I am using a diameter of .020. Also a good idea is to get a nice solder stand. The one I have was reasonably priced and allows me too gently pull and I have enough solder. I am not fighting with tangled solder or solder that keeps
rolling off the desk. When you solder there is smoke and it's a good idea to pickup a fume fan of some type. I purchased the Fume trap brand of fans. It works great and keeps the fumes away from you breathing them in.  You then have the hand tools that again have to be chosen and purchased wisely. You don't have to break the bank but don't go for super cheap. For this job I will be using my screw drivers, tweezers and diagonal cutters. Finally with this project I have to remove old solder from the pads that are on the K3's PC board. This is a part of the project if things go bad they can go really bad! In the past I have used the hand held spring loaded desoldering pump. They are ok but not great, I took the plunge and purchased the Hakko 808 desoldering tool. This has been one my best investments! This are most of the tools that I am going to be using and for this post that's about all I'm going to talk about. My next post (part 2) I am going to get into the steps I used to change P30 and P35 headers.



Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

Sharp-eyed Roger, G3XBM, has brought attention to the recent news of a new amateur allocation granted to South Africa's amateur radio community! It's just a small slice of a band but in an exceptionally interesting part of the spectrum ... 40MHz!

Amateurs have been given 'propagation studies' permission to transmit between 40.675MHz and 40.685MHz as 'primary users' and use up to 26dBW (400Watts) of power ... a healthy assignment.

I'm not sure where the push for this new band has risen from but no doubt from within the amateur radio community of South Africa ... and kudos to the SA radio authority for establishing this unique amateur band.

Myself and others, have often stated that an amateur allocation in the 40MHz region would be a wonderful part of the spectrum in which to experiment. Almost midway between the two "magic bands" (10m and 6m), the propagation opportunities of 40MHz would be most unique and abundant.

With Solar Cycle 24 being such a weak cycle, most of North America and particularly the western half, saw almost no F2 openings of any significance. Absent were the all-day long bone-crushing signals from the east coast, followed by the spotlight propagation-sweep down to South and Central America and finally over to Japan for another few hours of ear-shattering JA signals ... none of this for Cycle 24. Yet, in spite of the lower MUF's, I noted dozens and dozens of days when the F2 MUF would shoot up to the high 43MHz region and hang in for hours and hours ... just as it did on 6m in previous cycles.

Having even a small slice of spectrum at 40MHz would give amateurs a golden opportunity to follow some exceptionally interesting propagation trends during the next few cycles ... all predicted to be stinkers, some saying even worse than '24'. With 40MHz supporting the F2, Es, TEP and Auroral modes, there would be much exciting propagation to support activity in this region.

Maybe it's time North American amateur's start talking about a new slice of the 40MHz pie ... surely there is enough space to share.
Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

Here is this week’s space weather and geophysical report, issued 2015 Apr 06 0133 UTC.

Highlights of Solar and Geomagnetic Activity
30 March – 05 April 2015

Solar activity was at low levels throughout the period. Region 2303
(N19, L=066, class/area=Hkx/400 on 17 Mar) produced low to mid-level
C-class activity early in the period while Regions 2318 (N10, L=199,
class/area=Dao/199 on 05 Apr) and 2320 (S12, L=212,
class/area=Dai/140 on 05 Apr) each produced only low-level C-class
flare activity throughout the remainder of the period.

A filament eruption centered near S29E28 was observed in SDO/AIA 193
imagery between 04/2225-2330 UTC. A long-duration C3/1f hyderflare
was measured during this event and had an associated Type-II radio
emission. The subsequent fast-moving coronal mass ejection (CME) was
first observed in SOHO/LASCO C2 coronagraph imagery beginning at
04/2336 UTC. WSA-ENLIL model output suggests a glancing blow arrival
of this CME late on 07 April.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal levels on 30 Mar and normal to moderate levels on 31 Mar-05
Apr.

Geomagnetic field activity was at quiet to unsettled levels on 02-04
Apr with an isolated period of active conditions observed between
2100-2359 UTC on 02 Apr due to the effects of a positive polarity
coronal hole high speed stream. Quiet to unsettled levels were
observed on 30 Mar-01 Apr, and 05 Apr under a mostly nominal solar
wind environment.

Forecast of Solar and Geomagnetic Activity
06 April – 02 May 2015

Solar activity is expected to be low (below NOAA Scale event
thresholds) with a slight chance for M-class (R1-Minor) flare
activity throughout the outlook period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to reach high levels on 22-24 Apr and 02 May, moderate
levels on 06-08, 11-14, 17, 20-21 Apr, and 27 Apr-01 May, and at
normal levels for the remainder of the period.

Geomagnetic field activity is expected to be at G1 (Minor)
geomagnetic storm levels on 15-16, 18-19, and 25-27 Apr due to
coronal hole high speed stream effects. Active conditions are
expected on 07-09 Apr due to the anticipated arrival of the 04/05
Apr CME. Active conditions are expected on 17, 20 Apr, and 28 Apr-01
May due to coronal hole high speed stream effects with generally
quiet to unsettled levels likely for the remainder of the period.

Don’t forget to visit our live space weather and radio propagation web site, at: http://SunSpotWatch.com/

Live Aurora mapping is at http://aurora.sunspotwatch.com/

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I see that Martin Lynch is now selling the FT817ND for £449.95 (including VAT) which I guess is reflecting the exchange rate against the yen? Years ago it sold for less than £350 with VAT. I think the dealers are still making healthy profits? Why is this like fuel? When prices go up we soon hear about it. When price or exchange rates massively improve the suppliers are generally slow to respond.

Supply and demand?   People are prepared to buy at silly prices and dealers are happy to make good profits whilst they can. At one time a few years ago £1 would get you about 125 Yen. Today £1 gets you more like 175 Yen. Have prices followed? Of course not! Don’t be silly – just a bit cheaper!

It would be nice if they were clearing stock ready for a newer model. Sadly, I doubt this is the case.

See https://sites.google.com/site/g3xbmqrp3/hf/ft817 .

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Read it first hand in: www.icasa.org.za/Portals/0/Regulations/Working%20Docmuents/Radio%20Frequency%20Spectrum%20Regulations/RFSR2015.pdf

In South Africa the latest radio regulations permit the use by radio amateurs of 26dBW (400W) on a 10kHz wide band 40.675 – 40.685MHz “for propagation studies only”.    Now this is exactly what OFCOM should have done in the interest of real radio-science research.  Personally I think a wider band would be better, but how far sighted to allocate this at all.  Well done S.Africa.

OK, I  could pay £50 for a special research permit, but this is exactly what radio amateurs need for real self training and radio-science research.  The take-up might be small, but real research would take place.

OFCOM/RSGB – how about it please? You have just allocated 2MHz (2 chunks of 1MHz) of spectrum that will be used by just a handful mainly for DTV tests.  How about a much smaller slice somewhere really useful in the radio spectrum? 40MHz is mid-way between 10m and 6m, so ideal for Es tests and TEP tests over the equator.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

http://www.hamradio.com/detail.cfm?pid=71-001812

The price here in the UK started out at £1279.95, (e.g. Martin Lynch and Waters and Stanton) which seemed high to me. The rig looks very attractive at the right price, but I think UK dealers are banking on “early adopters” who want a new radio at silly prices. Greed? Who said that? Surely not! Prices are a little cheaper in the USA  but not sure of VAT and duty or guarantee.  The usual guarantee from the big UK dealers on Yaesu products is 2 years, but it is wise to check.  Also, further discounts may be offered if paying cash.  I can wait and wait!   £999 seems the right price, or even less.

The latest edition of Practical Wireless shows Haydon Communication now selling it at £1099.99. I assume this price includes VAT.  I can see others matching or bettering this price when the “early adopters” have had their day.

The rig covers all modes 160m-70cms and includes a limited range internal ATU and a colour touch screen. It also supports Yaesu’s C4FM digital mode. Nice radio, at the right price. I expect the UK price will soon be £999. Wait.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.