Merry Christmas & Happy New Year 2009
I'd like to take this time to wish all of you a very Merry Christmas.
This is a season of giving, peace, understanding and goodwill among all. I hope that this Christmas will find you among friends and family with good food, good times, and good memories. And I hope too that Santa lines the bottom of your Christmas tree with all the Amateur Radio goodies that it can hold!
Wish you a very happy new year, many nice DX contacts, a lot of pleasure with our hobby and see You in 2009 again!
The life of accu cells is depending on the style of use. Not proper accu discharning and charging is a short way to destroy them. Many amateur transceivers are able to work also on low voltage except the accumulator is fully discharged. So how to measure the voltage without voltmeter or multimeter on portable?
Simple indicators are showing only two states – charged and discharged. This is not enough to plan operation and early know when is accumlator low. Described indicator is measuring voltage in 5-steps, it's easy to build and cheap.
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From the 12th-19th Oct 2006 we will be PMTDX-Group (Purple Mug Team DX Group) active from the Island of ALDERNEY EU114 Guernsey and Dependencies like MU5W.
One of them is Oliver - MW3SDO, the second is Anthony - MW0JZE from LLanelli in South Wales and third is well know Tim - M3SDE from Coventry in UK. Tim is also a QSL manager. QSL details are on QRZ.com, bureau QSL are welcome.
All three guys will be on for full CQWW contest this weekend. They will work as multi operator with one radio, using only 100W and two antennas - Mosley beam for 10-15-20 and Carolina Windom 160 special for 160-80-40. |
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Transceivers with an output around 5W (CB transceivers, VHF handhelds, QRP rigs) are needing around 1,5A DC current and 13,8V voltage. Favourite ICs 7812 have an internal current limitation on 1A. That's the reason why are they used only like reference stabilisator in bigger power supplies.
Power supply with special ICs like LM723 are unnecessarilly comlicated. PSU with Zener diode like reference voltage are not very favourite. Many constructors are forgotting on stabilisators with 1.5 or 3A currents.
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Tube Data Sheet Locator Personal edition (TDSL), is an electronic datasheet that covers more than 19-thousands tubes. It was written by Duncan Munro with a help from Steve Bench. You can obtain and use this program for free. Upgrade with new sheets costs 29,95$.
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The 2006 Jamboree on the Air is taking place over the weekend of 21 and 22 October.
The Jamboree-on-the-Air, or JOTA, is an annual Scouting and amateur radio event sponsored by the World Scout Bureau of the World Organization of the Scout Movement. Thousands of amateur radio stations around the world participate. If the conditions are right, it is common to contact a hundred Scouting countries during the weekend.
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 Did you ever see the Earth from the Space? No? So SatScape, satellite prediction software, does it makes for you... Satscape produces real-time displays of where any Satellite is, and predicts passes for your locale. This program displays the position of satellites in an attractive graphic table and also generates lists and statistics with extensive information about satellites and the tracking process.
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 The reasons why are DK7ZB yagis popular are following reasons: very good performance and easy building.
We are using DK7ZB yagis too. In recent years we have build:
2 x 3el. 2m 50 ohm crossed for SAT operation
5el. 2m 28ohm for portable use
7el. 2m 28 ohm two stacked antennas
8el. 2m 28 ohm
9el. 2m 28 ohm, two piecs
17el. 2m 28 ohm rope yagi
13el. 70cm 28 ohm, two pieces
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Directional antennas like yagi or quad is requiring an antenna rotator. It's possible to work without it but it's a great disadvantage. Only if you can operate with a few fixed directional antennas and swith them is really to forgot on antennas rotators.
On the market is a cheap TV rotator named AR-300 XL (or similar) which you could obtain around 50 pounds in Radio Shack. What can this rotor do?
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The Yaesu FT-857 is very useful transceiver. Satellite requirements are sometimes very hard and this rig could not be used for it without some improvements. The sensitivity especially on 70cm band is poor. This can be solved by a suitable preamplifier. Other problem of FT-857 transceiver (and similar RIGs) is a twinband power amplifier. Spurious products from 70cm's output could desense reception on 2m downlink how is used on VO-52 sat. How to solve this problem? Build 70cm filter for Yaesu FT-857 yourself!
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