Category: in English

HAMsmithing – October 2017

Here are two small projects for the beginning of this month.

12V to 10V Adapter Cable for Baofeng UV-5R Charging

A common mistake made is using a cigarette lighter power cord for powering the Baofeng UV-5R Charger. Problem is that the charger needs 10V and not the battery 12.8V, much less the 13.8V when a car battery is charged.

My solution was to make an adapter cable with a resistor inline to drop the voltage to a bit more than the 10V spec’ed.

web-IGP4067

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A Small, Pocketable Antenna Kit for Handheld Radios

I call it the Giveaway Antenna Kit. Because it has the capability to be adapted to any handheld radio, that is, the antenna connector style of any handheld radio. So you can have it in your larger radio kit, and give it away to anyone in need without bothering for compatibility with his radio.

The basic idea stems from this idea by Bret of Survival Comms Youtube Channel . The use of the handheld radio’s own (actually aftermarket improved) antenna on a groundplane kit. In my built, the groundplane (radials’) kit is much simpler and easier to use. You just attach the antenna kit wire to fit your HT.

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Construction

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HAMsmithing – September 2017

Just as September was ending, I spent quite some time on small HAM projects.

1. I received the connectors and cables I ordered, so I sat down making cables for each DIY antenna I have.

2. I used some leftover PVC pipe to add 2 more sections in my collapsible antenna pole. Each section is 130cm (about 1.5 yards long), the wider my car trunk will allow. That makes for about 7 yards total height, just short of what one would need to make a sloping longwire antenna.

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A Small Source for Common HAM Radio Cheat Sheets.

I just stumbled on this webpage.

It is the manual and cheat sheets download page for the Multnomah County ARES group.

Obviously it just contains material for the radios they use, nevertheless it is no big sin to exploit their bandwidth and download the cheat sheet for your radio if it fits.

http://www.multnomahares.org/resources/equipment-manuals/

A Practical Interpretation of Antenna Gain, donuts included.

Antenna gain is not an easy notion for a new radio operator to pick up. Some even go as far as supposing that the antenna gain shows the increase in radio power.

But is not that the actual energy radiated is increased by the better antenna, this is not allowed by the law of the conservation of energy. It is because the radiated energy is handled, shaped-formed and directed better towards you.

A look at wikipedia tells us: ” In electromagnetics, an antenna’s power gain or simply gain is a key performance number which combines the antenna’s directivity and electrical efficiency. In a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction. In a receiving antenna, the gain describes how well the antenna converts radio waves arriving from a specified direction into electrical power.”

Now this explanation is correct but let’s make it simpler.

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HAMsmithing July 2017

This is a DIY USB charging cable for my Kenwood TH-F6A/F7E handheld radio.

web-IGP3869It is the same concept like the Baofeng USB to 10V charging cables that are found on eBay and amazon. But the virtue of the Kenwood HT is that it accepts a wide array of operating and charging voltage. Plugged to a 12V source it both charges and operates.

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