|N2UHC/B 10 Meter Beacon|
If you hear my beacon, please let me know at firstname.lastname@example.org.
Or you can write to me at:
Frontenac, KS 66763 USA
I will gladly reply with a QSL. Be sure to include UTC date & time and the beacon's message.
Frequency: 28.233 MHZ
Power: 4 Watts
Transmitter: Converted Midland 77-830 CB
Antenna: Vertical dipole
Location: Pittsburg, KS EM27pk
|My 10 meter propagation beacon is a converted Midland 77-830 CB which was converted to 10 meters by replacing a crystal. I replaced the 10.695 crystal with a 9.535 crystal which shifted the channels up into the 10 meter band, including several channels in the beacon band.
My first beacon was a similar CB modification using a Midland 13-830 which first went on the air on August 6, 2003 and operated on 28.232 MHZ. It worked faithfully for a couple years, but for some reason stopped transmitting. The story of getting my first beacon on the air can be read here. My beacon was off the air for about a year when I found an old 77-830 which is very similar to the 13-830 model, except that it is a 40 channel version instead of 23. I knew it would be easy to convert to 10 meters so I bought it and turned it into a beacon. My current beacon went on the air on Sept. 18, 2006.
When I modified my first beacon, I was only able to get 2 watts out of the CB transmitter. However, with the 77-830 modification I was able to get the full 4 watt output. The converted CB seems to operate fine at full power keyed in CW, and does not run hot so no cooling fan is necessary.
The beacon uses a Norcal keyer kit as a controller. The programmed PIC chip keyer has a beacon mode which allows one or two memories to be transmitted n a loop. I did, however, replace the Norcal chip with the Jackson Harbor PK-4 keyer chip, which has the same pinout but has a few more features than the stock Norcal chip. The keyer keys the unmodulated AM carrier of the CB to give a pure CW signal.
|Vertical 10 meter dipole antenna|
|The beacon antenna is a homebrew vertical 10 meter dipole built from electrical conduit.
The beacon uses a battery backup system in case of power failure. A 12V 17.2 Ah gel cell battery is connected in parallel with the power supply to provide instant backup power. Use of a couple of diodes and a resistor provide flawless switchover during power failure and restoration of mains power. The first diode is placed in series with the power cord to keep the battery from being drained through the power supply when turned off. The second diode provides power from the battery and bypasses the resistor, which allows the battery to be trickle charged when the power supply is on.
|My first beacon|
|The faceplate of the radio is the original from the CB, and in fact the one on this beacon is the same faceplate from my old beacon. The new beacon looks very similar to the old one. I did make some modifications and changed the button style. Since I'm not concerned with changing frequency of the beacon, I cut the shaft of the channel selector switch. It is still long enough to turn in case I ever need to change frequency, but is hidden behind the faceplate. In its place on the faceplate I covered the hole with a piece of PC board, drilled a hole through it and installed an LED which lights as the beacon transmits. The new buttons were salvaged from an old printer, and I made labels to put on the faces of the buttons. A push-on, push-off switch was installed in the left side as a power switch.
In the window of the channel dial, I placed a piece of paper on which i had printed the word "Power." I cut a piece of clear plastic which I placed behind that. Behind the plastic part I installed a super bright LED where the original channel dial lamp was installed. At first I tried a bright red LED, but then I experimented with a white one, which has a blue tinge. I liked the blue better so I used that, along with putting a piece of clear blue plastic behind the thick plastic piece. This gives the power indicator a nice blue glow. Next to the channel display was the old TX lamp indicator. I removed that and left a hole for the piezo speaker of the controller, which I mounted behind the faceplate.
As a final touch I was going to install another LED behind the meter in place of the 12V lamp, since the lamp wasn't very bright. But I knew that I could not mount it in such a way as to light the whole lamp, since LED's have a narrow beam as compared to incandescent lamps. So I removed the lamp altogether to save current when the beacon was running off the battery.
|Beacon installed & operating|
|I have obtained another Midland 13-830 CB which I am in the process of converting to 10 meters for use as a backup beacon in case the first one fails or has to be taken out of service for maintenance. The power connector will be the same so I won't have to worry about an adaptor or anything. Since it will be essentially the same as the main beacon it will be easy to swap them out. The same kind of keyer will be installed.|
|Ten-Ten club 10 meter beacon list
10mbeacons.com has links to the 10M beacon spotter page & chat room
WJ5O's ten meter page has lots of info about 10 meters, plus beacon info
AC6V beacon page, lots of beacon info & links to other beacon lists
G0AEV's beacon website has lots of info, plus the HF beacons mailing list
KL7FDQ's beacon website page has links to many 10 meter beacon websites
G4TMV's beacon website has links, QSL's, and recordings of various beacons
N7LT's beacon website has info about his 6 & 10 meter beacons, plus links to other beacon sites
LOWFER beacon MO is a lowfer beacon operated by a friend of mine in Seneca, MO