Thursday, March 31, 2011

Bureaucratics

No, I'm not going to complain about bureaucratics or office life. I'd like to draw your attention instead to a photographic exhibition I found online.
I've always felt more comfortable around old books & had a lifetime interest with printing and the technology that makes it possible. That is why I started looking through the photographs but not why I kept looking until I had seen every one.
This exhibition makes it possible to compare and contrast the different lives of people who spend their lives shuffling paperwork and managing the flow of information that modern society generates.
Be sure to look through the text below each photograph and note the small personal details and salary information of each person featured.

Click on the photograph below to enter the exhibition:

India, Bihar, bureaucracy, 2003. Typeroom in the Finance Department of "the Old Secretariat" in the state capital Patna. The seemingly rusty old typewriters are awaiting use: the department is supposed to be 40% understaffed. The presence of several snoring employees gives a different suggestion.

Monday, March 28, 2011

Spinning the Sun's Rays Into Fuel - ScienceNOW

A development that, if deployable in an economical manner, could radically change the way we generate energy.


Researchers at the Massachusetts Institute of Technology (MIT) in Cambridge have created a potentially cheap, practical artificial leaf that does much the same thing—providing a potentially limitless source of energy that’s easy to tap.

Click here to read more:  Spinning the Sun's Rays Into Fuel - ScienceNOW

This is a book store! - The Ateneo Grand Splendid

There isn't much more I could say about this book store in Argentina. Just take a look at the photographs:


If you have a garden and a library, you have everything you need.  ~ Cicero


Today, with books and movies more expensive than ever, and television entertainment in free fall to the lowest level of stupidity, free circulating books are an absolute necessity. They are quite simply another kind of food. For those without money, the road to the treasure house of the imagination begins at the public library." ~ Columnist Pete Hamill, New York Daily News


A library is thought in cold storage. ~ Herbert Samuel


Wednesday, March 23, 2011

The Aurora

As amateur radio operators we are aware, more then most, of the constantly changing environment of charged particles above our heads. The way radio signals bounce off the ionosphere allows our relatively low power transmissions to skip across huge distances, sometimes completely around the world if the ionospheric conditions are right.
To the layperson this is sometimes hard to visualize but the video below shows spectacularly the result of charged particles that are ejected by the sun, interacting with the geomagnetic field that shields the Earth.

Tuesday, March 22, 2011

Japan Radiation Levels - More information, less hysteria.

There has been a lot of media attention focused on Japan lately. The large majority of reports have been short on details and long on emotional language. If you believe the worst of it then we're about to witness a mushroom cloud of epic proportions rise above Japan and drift over our heads spreading radioactive death from above.
The truth, at the moment, is a little less dramatic and requires more time to explain than a typical five minute news bite. The website http://www.cbryanjones.com/journal/2011/3/19/japan-radiation-levels-in-english.html has done an excellent job of mapping the relative radiation levels around Japan and explaining what the levels mean in terms of background exposure or medical procedure exposure.
Please take the time to read the complete page including the summary at the end, it is well worth your time.

Monday, March 21, 2011

When the going gets tough, the tough get transmitting.

Its becoming easier to list the states I still require for "Worked All States" which is a good thing!
I've noticed that I now recognize the call signs of the 'regulars' on 40M digital modes & have taken to using Olivia and Contesta when the opportunity presents itself to contact different people.
The going gets harder now and some of the states are small, with less people, or sparsely populated ... with less people. Less people = less hams and a small possibility of contacting those remaining states.
Still, it makes contacting the remaining states all the more satisfying when I get to cross them off the list.

The states in yellow are those I still need to contact ...

Friday, March 18, 2011

First week of Japan disaster

The following is a statement from the Chairman IARU Region 3 Disaster Communications Committee:


The Japan Amateur Radio League (JARL) HQ station JA1RL and other amateur radio stations are maintaining the effort to support disaster relief operation which is being captured by audio and vision.

IARU Region 3 Secretary, Ken Yamamoto JA1CJP said in less damaged areas, the power supply is being restored gradually and local amateur radio club members have started to establish stations at shelters either on HF, VHF or UHF bands.

Ken Yamamoto said, “The radio amateurs in the affected areas are also making use of UHF repeaters for communications between shelters and local disaster relief centres.

“According to reports from the shelters, they are generally shortages of food, drinking water, fuel and medical goods. This is mainly due to difficulty of transportation because of road situation and staff shortage.”

He said JA1RL continues to operate under instruction to be an emergency traffic centre. Using the 7 MHz, 144 MHz and 430 MHz bands it is receiving help from JARL members in the affected areas.

Field stations are using various frequencies, including some battery powered and others using small generators. Each is exchanging rescue and disaster relief operation information with JA1RL and others.

While 3525, 7030, 7043 and 7075 have been mentioned as in use, it's wise to keep those, and all of the Centre of Emergency frequencies clear of normal and non-urgent traffic. There is no call for additional foreign radio amateurs.

Ken JA1CJP notes that JARL has received many e-mail messages from radio amateur radio societies and individual hams of many nations and territories in all six continents.

“These messages convey their condolences, sympathies and prayers for the people in Japan. JARL appreciates them very much and is encouraged by them,” he said.

“I have also picked up some update information from news sources. The situation is getting worse. On March 17, police announced 5,178 people have been killed and 8,913 are missing. The numbers are sharply rising as most affected areas become accessible by search and rescue teams,” he said.

The teams are from Australia, China, Korea, Singapore, New Zealand, USA, Germany, Switzerland and Russia.

The status of Fukushima nuclear plant is still serious and local residents within 20km radius have been evacuated.

It has been a week since the 8.9 on the Richter scale quake, the worst in 140 years, hit off Sendai triggering a ten-metre tsunami.

Statements issued by Vertex Standard Yaesu said its centre at Fukushima was currently out of action, while Icom and Kenwood are located elsewhere and not suffered the same outage. No reports have been received from other manufacturers at this time.


Jim Linton, VK3PC

Chairman IARU Region 3 Disaster Communications Committee

Thursday, March 17, 2011

The Secret Life of Machines - Radio

At some point in the distant past I was able to download all of the episodes of "The Secret Life of Machines" and I now have them on my media player at home to watch whenever I get a moment.
I've always enjoyed the presentations of Tim Hunkin & Rex Garrod, they go to great lengths to make technology understandable. 
I recommend you go to their website - www.secretlifeofmachines.com - and check out the additional material. Tim and Rex won't sell you the DVDs of their show, instead they GIVE the episodes away. There are links to a variety of formats you can download, so get them while they last!



Heathkit IT-22b Capaci-Tester



Heathkit Capaci-Tester IT-22b
One of the pieces of test equipment I brought home from the last hamfest was the Heathkit IT-22b Capaci-Tester.
It is a fairly simple piece of equipment designed to test capacitors for shorts or open circuits.
A critical piece of information I learnt while researching this tester was that it is NOT designed to test electrolytic capacitors despite having what looks like DC red & black connectors on the front.
Instead of a meter is has a 'magic eye' tube which uses a vacuum fluorescent display and electronically deflected shadow wedge to indicate the state of the component under test.
For an excellent display of 'magic eye' tubes take a look at www.magiceyetubes.com
For more information on the Heathkit IT-22b take a look at the information provided by Joe Sousa at www.radiomuseum.org and included below.



Fellow Radiophiles,
I present here a functional analysis for each position of the rotary switch of the IT-22 capaci-tester. I don't have access to a manual, I am working with the schematic and a picture of the front panel.
Another description of the test capabilities is at http://www.heathkit-museum.com/test/hvmct-1.shtml
According to this link, this tester does not check leakage or electrolytic caps. Note that the test signals used by the tester are all AC type signals at 19MHz for opens and 60Hz for shorts. No DC bias is provided for electrolytics. The primary usefulness of this tester is the ability to test non-electrolytic paper, mica, film or ceramic capacitors for shorts or opens, without removing them from the Radio or TV.
It would be good to see a set of operating instructions for this IT-22 set.
Before I start on the general functionality, note that there is no DC power supply. The eye target anode and triode plate only work on the positive halves of the 540VAC power transformer secondary. The 55VAC winding provides a bias that is negative when the tube is active on the positive halves of the 540VAC winding. One drawback of this approach is that the eye pattern may not be as sharp as with a DC supply.


Heathkit IT-22 front panel
I will refer to the switch drawing in the schematic, and rotate the switch clock-wise, starting from the OFF position. The front panel shows 5 switch positions with OFF at the center:

  • Short Test
  • Short Check
  • AC OFF
  • Open Check
  • Open Test








Position Short Test 
The control grid is connected to the Red test lead and to the negative bias source provided by R1 and R2, via taps 4+5+10. This is a DC test because the Hartley oscillator is disabled, and the test is conducted during the positive half cycles of the 540VAC power transformer winding. A shorted input capacitor opens the eye. A good capacitor under 1uF will close the eye. The absence of a capacitor at the leads also closes the eye. The reactance of 1uF at 60Hz is 2.6k, which will start to load the R1R2 significantly. Above 1uF, the eye should start to open up due to the low capacitive reactance. The CT-1 instructions at the link above say that this test works for capacitances up to 20uF. Larger capacitances look like a short.
Position Short Check 
The control grid is grounded by taps 5+9. The triode plate and deflection anode go to a low voltage and open the eye. The Red test lead is open. The LC circuitry at the cathode is prevented from spurious oscillation by the R4=3.3K damping resistor. This test is meant to warm up the unit from the off position and the capacitor should not be tested until the eye is completely open in this position.
Position AC OFF 
The slaved power switch in series with the power transformer is open. A 3.3k resistor shunts away any charge present at the capacitor to be tested.
Position Open Check 
Switch taps 9+10+11 are grounded, thus shorting out the cap under test without any current limiting resistor, before any tests are conducted. The control grid is tied to C5 via switch taps 5+2, thus completing the feedback loop of a Hartley oscillator via L1B. The -8V DC grid leak bias that develops at the grid due to the Hartley oscillation, cuts off the triode. The resulting high voltage at the triode plate and deflecting anode close the eye completely. The oscillation frequency for the similar CT-1 model is19MHz. This test is meant to warm up the unit from the off position and the capacitor should not be tested until the eye is completely closed in this position.
Position Open Test 
The Hartley oscillator loop is still closed by taps 5+2. The oscillator coil secondary L1A is now tied to the active RED test input  via C6=470pF. R4=3.3k is still in parallel with the capacitor input. A non-shorted capacitor greater than 50pF at the input will lower the oscillating frequency to a point that oscillator amplitude is much lower, or extinguished. The -8V grid leak bias is thus reduced and the eye closes. The reduction in oscillation amplitude with at lower frequencies is due to the Q of the inductor being dominated by series resistance of the L1 inductor, in particular the L1a winding that is loaded by the cap under test. A shorted cap will also close the eye, so the short test should be done first.
Corrections and comments are invited.
Regards,
-Joe


Heathkit IT-22 Capaci-Tester circuit diagram






Thursday, March 10, 2011

Hallicrafters HT-9

This would be the PERFECT partner for the Hallicrafters SX-25 ... but I don't hold out much hope of finding one. What a beast of a transmitter ... 165lbs of heavy metal!


Hallicrafters HT-9

Modes: AM/CW
Bands: 80, 40, 20, 10 Meters (plug-in coil set + band switch)
Power Output: 75W-AM, 100W-CW
VFO: No
Power Supply: Internal
Final Tube(s): 814
Modulator Tube(s): 4 ea. 6L6
New Price/Year: $199.99-$225/1940-1948
Size: 12.5"h x 29.25"w x 20.5"d
Approx. Weight: 165 lbs

Hallicrafters Super Defiant SX-25 and Hallicrafters PM-23 Speaker

I may have brought back a trunk load of equipment from the Hamfest but this was worth the trip by itself.

I purchased the SX-25 from the Greater Houston Hamfest and the PM-23 speaker from Robert's Military Radios

The manual for the SX-25 is available here : Hallicrafters_SX-25_Manual

Robert is a great guy who specializes in military radio hardware and documentation. If you need anything related to military radios go look him up!

Hallicrafters Super Defiant SX-25 and Hallicrafters PM-23 Speaker

Here is some information regarding the SX-25 for your reading pleasure.

The Hallicrafters SX-25 Super Defiant receiver was manufactured from 1940 to 1946. It was touted to have better performance than that of the famed Hallicrafters SX-17 receiver. Among its outstanding advantages were extreme selectivity and more and better audio. 

The design of the crystal filter made possible critical CW operation under trying conditions of intereference. The sensitivity of the receiver is raised from 2.8 to 4 times in the "CW Xtal" position when the receiver is tuned to the exact resonant frequency of the crystal itself. 

Both IF stages are expanded in the "Broad IF" position for high fidelity performance. The A.N.L. reduces interference by as much as 70%. 

The Hallicrafters Super Defiant SX-25 receiver complete with the Hallicrafters PM-23 Speaker, Crystal and 12 Tubes sold for $99.50. It weighs 46 pounds.
The Hallicrafters SX-25 covers 5.5 MHz ti 42 MHz in 4 bands. The separate calibrated bandspread dial for the 10, 20, 40 and 80 meter bands provides frequency meter tuning.

The Hallicrafters SX-25 is a single conversion superheterodyne communications receiver with 12 tubes. It uses two 6F6 tubes in the audio amplifier section and produces wonderful sound.


Information from : http://www.hug-a-bug.com/SX-25.html

How many hams from years ago started to save their pennies after seeing this ad ...
Image from : http://www.ohio.edu/people/postr/bapix/SX25.htm

Tuesday, March 1, 2011

Automatic upload to ARRL Log Book of the World from Ham Radio Deluxe

This handy utility automates the uploading of your log file to several different online log books. There are two versions for HRD 4 & HRD 5 so make sure you get the right version.

Setup was simple and took less time than signing and uploading a single ADIF file to LoTW.

I would suggest changing the default upload interval on the setup screen to at least a few hours so you don't hammer the servers at ARRL.

Click here to check out WD5AEA's excellent utility.

Automated LoTW uploads, import LoTW confirmations, logbook updates from QRZ.com, import eQSL confirmations, download eQSL card images, generate GlobalQSL ADIF upload files, update personal information in the HRD logbook, generate HTML logbooks for your web site and more.

Perhaps someday ...

I've been slowly acquiring parts for a home built 'something' with vacuum tubes.

As I already have some tube receivers perhaps I should be looking at a transmitter ... what to build though?

I'm hoping the next ham swap-meet will provide some inspiration in the form of parts or perhaps something that can be rebuilt. I would like to put together a low power AM rig to experiment with & later use as an exciter in conjunction with a power amplifier.

My ideas are a bit fuzzy at the moment but I found a series modulated low power AM transmitter circuit diagram on-line which looks promising. It does without the modulation transformer which can be a very hard to find component for home-brewers.


 Five Watt Series Modulated Rig by Tom, K1JJ

No modualtion transformer is required. This rig is capable of clean audio from 10 Hz to 15 kHz. The VXO can "pull" the crystal up or down a few kHz with good stability. Only 3 or 4 crystals could cover the entire AM Window on 75 Meters. For complete crystal stability short out the VXO cap and inductor to ground. The crystal will now determine the frequency and not be able to move crystal 3 kHz as before. Recommend using a filament transformer for the final amp tube rated at 1500 VDC insulation. Be careful. Remember, the cathode of this tube is at 300 volts or more.


Note on diode string: Start with 35 diodes.Use a three position toggle switch for S1. The High setting shorts out about 1/3 of the diodes in the string. Thi setting yields about 5 watts output with 100% positive peak modulation capability. The Lo position shorts out about 2/3's of the diodes. This setting yields about 2 watts output with 200 % positive peak modulation capability. The third position (not shown) shorts out none of the diodes. This setting yields about 500 milliwatts output with 300 % positive peak modulation capability. You SHOULD play around with the numbers of diodes shorted to suite your tastes.