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Activities at Amateur Radio Station VE3OAT

Main Interests at VE3OAT

High levels of local interference from neighbours' switching-mode power supplies, LED lights and maybe plasma TV sets as well have kept me off the air during recent years.  (See also the section following.)  In the past, major activities at VE3OAT have included the following :

I will add more details about these activities as I find time.

Radio Frequency Interference (RFI)

Currently, most of these activities have been severely curtailed by heavy radio frequency interference (RFI) on almost all HF bands from two solar panel installation less than one kilometre from my home.  Curiously, radio interference from these installations seem to be suppressed (filtered at source) on frequencies below 2 MHz but not above 2 MHz.  The interference is very strong on the 80 through 30 metre bands. 

In spite of the interfering noise (or, perhaps because of it), I have begun activity on the 160 m band using the new digital mode FT8 (part of the WSJT-X software package) and getting reasonable results.  It helps that I have installed a small, active, receive-only magnetic loop antenna which is oriented to null-out at least some of the noise from the direction of its source.  Transmitting is accomplished by shunt-feeding my 15-m tall tower which now has 20 ground radials, each a quarter-wavelength at 160 m.  Unfortunately, my property is longer than it is wide so the radials don't go very far in the north-south directions.  I might never make DXCC or even WAC with this set-up on the 160 m band but it is fun trying. 

Recent Project with a Chinese 102E Radio Set

Chinese 102E HF radio transmitter and rebuilt commercial power supply

A recent project was the building of a power supply for the transmitter from an old Chinese (PRC) Type 102E army radio set.  I don't have the matching receiver that was part of this set.  My project involved designing and building a suitable P.S. in the re-purposed cabinet of an old Swan 117XC P.S. unit.  (A big thanks to Frank, VE2KOI, for providing the Swan unit.)  There is nothing remarkable about the design or construction of the power supply except that, according to markings on the dial, the voltmeter I chose was originally used in the famous British Wireless Set No. 19 (which I have never owned).  Besides a suitable B+ voltage for the transmitter, the power supply provides 6 VDC for the transmitter's tube filaments.  I have ensured that this voltage is actually slightly less than the rated 6 V in order to prolong the life of the tubes. 

The Chinese transmitter provides CW, MCW and AM voice transmission capability over the 2 to 10 MHz range with about 10 watts output, and I hope to have it on the air as soon as I solve the local noise problem.  Here is a link to a nice article about the radio (receiver and transmitter) by Mark, NF6X.  The Chinese transmitter and my "new" power supply are shown below. 

RT-654A/TRC77 Receiver-Transmitter

RT-654A/TRC77 manpack HF radio

I have another "green" radio, bought many years ago on the surplus market, a TRC-77 (RT-654A) HF man-pack radio used by U.S. forces during the Vietnam War.  It was designed to receive AM and CW on six channels and to transmit CW on six channels (not necessarily the same channels) in the 3-8 MHz band with at least 10 W of output power.  It came with the original headset (and multipin connector) and a J37-type Morse key mounted on a leg-clamp.  I have crystalled it for CW frequencies in the 80 and 40 m bands.  (Please ignore the obviously reversed antenna connections in the photo above — the setup was hastily done just to take the picture.) 

Here is a nice article by N6CC about the TRC-77. 

Do You Belong to a Radio Club?

I support the following organizations with my membership :

Each of the national organizations (and many others around the world) is a member of the International Amateur Radio Union (IARU), an umbrella organization that, among other things, represents the Amateur Radio Service at international telecommunications conferences, especially those organized by the International Telecommunication Union (ITU), a world-wide organization of the United Nations.

If you are an Amateur radio operator, are you a member of your national Amateur Radio organization?

If you would like to become an Amateur radio operator, you can find excellent tutorial material at the Websites of the two national societies mentioned above, as well as at many others.  In addition, the Amateur radio clubs in many large cities organize classes to help students prepare for the licensing examinations, so check with your local Amateur radio club.