Is lead based solder banned for all electronic purposes?

KESTER SOLDER24-6040-0066Many sources on the internet seems to indicate that lead based solder is no longer possible to purchase and is in fact banned for use in electronics. However, this is not the case. It is correct that the EU has passed a regulative that prohibits the use of lead based solder in new consumer electronic products. However, the use of lead based solder for repair of older equipment is still perfectly OK as far as I know. Also, new military electronics is ok to manufacture with lead based solder. I was starting to worry about soldering problems that may affect many amateur radio projects like soldering PL259 coax connectors, after my supply of solder went out. With leadfree solder, a much higher temperature is often necessary to use. The center of the non teflon PL259 connectors then melts and several other problems occur. The leadfree solder doesn’t flow as well as lead based. I us the 60 Sn / 40Pb variant that has been the standard for decades. Farnell sells it and has it in stock.  I have replenished the stock to last for several years in different thicknesses so i have for SMD, hole mounted, plugs and larger devices.

Here are Farnell’s ordering codes for good old lead based solder:

1610446 SOLDER, 40/60 2.36MM 453G;
419310 SOLDER WIRE, 60/40, 1.63MM, 500G;
453614 SOLDER WIRE, 60/40, 1.0MM, 500G;
5090787 SOLDER WIRE, 60/40, 0.5MM, 250G;
5090830 SOLDER WIRE, 60/40, 0.7MM, 500G;

Just go ahead and order so you have solder supplies for hobby use for 30 years. Not easy to know what the bureaucrats in EU will think up next!

Analysis of a tank circuit and notch circuit with the DG8SAQ VNA

image series lc dip IMG_0459

Experiment 1: I did an S11 analysis with my VNA on a 500pF transmitting capacitor in parallel with an airwound copper coil of good cross section. The question is how to interpret the first picture. The voltage over the parallel circuit is in phase with the drive voltage and almost as high in amplitude as the drive voltage when there is a real component present. (Blue trace, left image). The drive voltage cannot drive a current when the circuit is in steady state oscillation since the circuit has almost the same voltage over it as the drive voltage itself. Low voltage differential, results in low current. This is the definition of high impedance. Low in frequency the resultant voltage is not in phase however the voltage amplitude close to the resonance is almost as high as the drive voltage. The circuit presents a inductive load. Above the frequency there is a change from inductive to capacitive load. (Red trace). It looks like the phase changes abruptly, but I interpret it as a high impedance that occurs only due to a change from high inductive to high capacitive voltage. The phase goes “over the top” but only since someone defined capacitive reactance as minus. The impedance is still high and almost real close to resonance. |Z| represents the resistance to AC current in this context. It is the length of the R+jX vector.

Experiment 2: after that I did a S21 sweep of the same components in a series notch configuration as per VE2AZX’s paper http://www.arrl.org/files/file/QEX_Next_Issue/Jan-Feb_2012/QEX_1_12_Audet.pdf  to try to determine the Q (of the coil primarily – I assumed the Q of the capacitor very high compared to the coils Q).

The second picture gives the notch depth so the Q can be calculated as per VE2AZX’s QEX paper http://www.arrl.org/files/file/QEX_Next_Issue/Jan-Feb_2012/QEX_1_12_Audet.pdf

Note1: the picture to the right is of the S21 test, not of the parallel circuit and the frequency may have changed slightly as the coil were changed between the two experiments if I recall correctly.

Note2: don’t worry about the long leads. This is an exercise in understanding the design and operation of antenna trap circuits and loss in reap circuits due to resistive losses in the inductor primarily. The leads would be almost as long in a real trap.

G4WPW microphone connector database

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G4WPW has made a nice database covering microphone adapters for most amateur transceivers. This is a good tool for contesters and DX-ers adapting microphones and headsets for their new radios. You can check out his webpage here http://homepage.ntlworld.com/rg4wpw/date.html

Antenna isolation calculator for colocated contest / DXpedition antennas

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I have made some quick isolation calculations (dB) for the scenario of two rigs with 100W output power collocated using two dipoles mounted some meters apart on the same support but with separate feedlines.

A Preliminary conclusion is that a BPF + notch is likely necessary for interference free operation. With good filters and notch, the second harmonic will be at a  7uV level and the hash will be at a S1 level on the antenna connector of RIGB which is equivalent to a moderately strong signal on 20m with low noise.  Without filters, the second harmonic will be S9+50dB. The phase noise "hash" will likely be at S3. This will likely be a significant problem.

Download the calculator here: isolation_calculator_nine_islands. The calculator is posted under a Free Beer license. You owe me a beer if you use it! Please give feedback and peer review the calculations.

Testing DxPatrol HF converter for Funcube dongle

DSC_6989

At Hamradio in Friedrichshafen I picked up a DxPatrol HF converter for the Funcube Dongle ( Supplier WiMo, designer: http://www.ct1ffu.com/site/ ). I was eager to test it on HF CW reception. To check the coarse frequency and operation of the local oscillator I used my Yaesu VX7R for detecting the signal from the board. (The DxPatrol HF converter can be given a voltage feed via the SMA from the Funcube Dongle, if you turn it on from your Funcube. Alternatively, you can feed it with power via the USB connector – only 5V and GND is connected internally of course. I wanted to check that the converter was operating by listening to the local osc with my VX7R).

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I was a bit surprised over the test result when listening to CW signals on HF. All the signals on the bands sounded like russian stations from the old days derifting all over the place. The local oscillator of the DxPatrol I purchased is unstable. It drifts so much that it can clearly be heard on CW. The designers of the DxPatrol unit told me to keep the unit free from wind when I asked about a possible design or osc issue via mail hehe 🙂 . I think a “slight mod” may be necessary … I have SI570 and a buffer in my mind….

SdrDx and Funcube dongle. Receiving airband traffic

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You should download and try out the new SdrDx console. It is compatible with your Funcube dongle. Finally a more advanced SDR console that has many of the features you need including several notch filters, memory functions, a very good and intuitive GUI. In fact I like the GUI style on this one! One minus is that it is not open source. The image above is a screen dump of Funcube receiver set to a QRG in the airband. The AM detector works very good. The SdrRx can be downloaded here at fyngyrz’s site  http://fyngyrz.com/?p=915

How to install SdrDx: Download zip. Unzip. Make a shortcut to the .exe file. If your Windows firewall gives you a warning, tell it to open up for that program. Make sure you have a new firmware installed on your Funcube (see other post for how to update).

Live status of amateur satellites

oscar_sat_status

Many radio amateurs find it difficult to find the real-time operational status of amateur satellites. The AMSAT website is not very good at showing real-time status in my personal opinion. If you have been looking for a way of finding the status of the birds like me, head over to http://oscar.dcarr.org/ for a real-time status based on thousands of reports from radio amateurs all over the world.

Currently these satellites are active with transponders (FM / SSB / CW) : AO-7 (launched in the seventies!), AO-27, FO-29, SO-50, VO52

Pictures from OH8X WPX SSB 2012

Here are some pictures from the WPX SSB 2012 at Radio Arcala. Enjoy!

DSC_5491_w800_txtDSC_5510_w800_txtDSC_5437_cpd_w800_lb3hc_v2_txt DSC_5535_w800_txtDSC_5519_w800_txtDSC_5534_w800_txtDSC_5470_w800_txtDSC_5462_w800_txtDSC_5274_w800_txtDSC_5283_w800_txtDSC_5351_w800
DSC_5342_w800_txtDSC_5418_w800_txtDSC_5277_w800_txtDSC_5306_w800_txt

                   CQWW WPX Contest, SSB

Call: OH8X
Operator(s): LB3HC, LA7JO, CU2DX, CU2CE
Station: OH8X

Class: M/S HP
QTH: Arcala
Operating Time (hrs): 48

Summary:
 Band  QSOs
------------
  160:   36
   80:  106
   40:  478
   20: 2259
   15: 1082
   10:  178
------------
Total: 4139  Prefixes = 1379  Total Score = 11,906,286

Club: Contest Club Finland

Comments:

Great to be back operating from Arcala now that the SSN is higher! All
operators: LB3HC, LA7JO, CU2DX, CU2CE had a great time and a lot of fun (as
usual from OH8X - Arcala). 

Thanks to OH2BH, OH8NC and OH6KN for hosting us! Also thanks to the rest of the
Arcala team for making this possible!

This time we also had time to take some HD video and wide angle pictures of the
station.

Plusses:
=========
This time we had relatively good conditions up here at 65 degrees north
latitude in the ice and snow.

No significant technical issues were experienced.

This station station is professionally built by the extremely skilled guys in
the Arcala team. Kudos!

The Arcala antenna park is nothing less than extreme.

It was nice running with the new Yaesu FT DX 5000. Yaesu did it again! 


Minuses:
=========
We were likely affected by aurora at several time periods during the contest
that affected rates. We were unable to achieve runs at 40 and 80 to DX
locations and that resulted in that the DX runs was worked on 20 and 15. That
cost us 6-3=3 points per DX QSO and our average QSO points were below target. 

Our target was to beat OH10X from 2011 and we wkd more mults, but somewhat less
QSOs corrected by the QSOs/36*48 factor due to condx and latitude (claimed
score). In fact 40 meter did not give good DX propagation at all.  OH10X is
approx 500 km to the south. 

We lost power due to a power company outage / spike at night and lost control
over all tower rotators and the voice keyer. It took several hours to correct
this.

Summary:
=========
WOW! What a station and what a team. Contesting has got a new meaning. 
Updated pictures will be posted at http://www.lb3hc.net

On behalf of the team 
LB3HC
Marius

WPX SSB meeting @ 65 degrees north – OH8X – Radio Arcala

Before LA7JO, LB3HC, CU2CE and CU2DX was working the WPX SSB 2012 contest from OH8X, we had  some very good time discussing conditions, radio contesting and amateur radio with the Arcala team and with our new friends from the Azores. On the below image from the left: Juha OH8NC, Marius LB3HC, Martti OH2BH, Jose CU2CE, Veijo OH6KN, Stig LA7JO and Francisco CU2DX.

DSC_5437_cpd_w800_lb3hc_v2

This was a very nice meeting at the Arcala Xtreme Station @ 65 degrees northern latitude. The Arcala team has an approach to amateur radio that is both social, technical, and serious. This time in nice weather with spring temperatures around the corner and snow melting. Check in later. More pictures and video from Arcala will be posted. And also check 3830 for contest results!