Convert a 23ch CB to 10m Beacon Transmitter
2
Radionut53 since 1998 convert a 23ch CB to 10m beacon transmitter Home CHATROOM - Come on in, have a chat! Website Suggestions and Questions Radio Repair corner Helpful online tools Androx's Corner Radio modifications and Information Shortwave, Scanner , CB, Ham radio pages For Sale: Replica radio operators tower's My Radio Shack links software My other Websites Computer Problems LOST WEBPAGES For sale or Trade The quickest and easiest way I have found to make a QUICK and EASY 10m rig. There must be millions of the older 23 channel CBs that use the 12 crystal synthesizer set-up with a 23 MHz oscillator and 14 MHz oscillator setup. Check "Garage Sales & Flea Markets" for the bargain rigs In this rig, the 23MHz signal mixes with the 14MHz signal to produce a signal in the 38MHz plus range. To receive, this 38MHz signal is mixed with the receive oscillator signal (11.730MHz) to have a signal that is 455KCs offset from the operating frequency. Example… 23.290MHz mixes with 14.950MHz for the 38.240 frequency and then mixed with 11.730 to get 26.510MHz …. This 26.510 is .455 lower than 26.965MHz which is channel one.. To Transmit, this 38MHz signal is mixed with the transmit oscillator signal (11.275) to have a 26.965MHz operating signal. Example…. For channel 23…. 23.540 mixes with 14.990 to get a 38.530MHz signal. The 38.530MHz signal is mixed with 11.275MHz for a 27.255MHz transmit signal. Now find a crystal from almost any 40 channel PLL controlled CB…… the reference frequency crystal is 10.240mhz (Most common ….. almost universal use by manufacturers)...... actually, a 10.180MHz or a 10.000MHz will work equally well...... it just causes the beacon frequency to be a different channel to start at 28.290MHz (with the 10.180MHz crystal... this starts at channel 19)... and (with the 10.000MHz crystal.... this starts at channel 5) Substitute the 10.240MHz crystal for the 11.275MHz transmit oscillator crystal.. Now, channel 1 becomes a transmit frequency of 28.000MHz. . Channel 10 becomes 28.110MHz. Channel 19 becomes 28.220MHz Channel 20 becomes 28.240MHz Channel 21 28.250MHz Channel 22 28.260MHz Channel 23 28.290MHz With a little capacitance added .... the crystal will "bend" a few Hertz either way. In parallel the frequency goes down ... in series, it goes up. I like to use a "trimmer" in series for frequency convert a 23ch CB to 10m beacon transmitter http://radionut53.tripod.com/id477.html 1 de 2 08/06/2011 10:48
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Transcript of Convert a 23ch CB to 10m Beacon Transmitter
Radionut53 since 1998convert a 23ch CB to 10m beacon transmitter
Home
CHATROOM - Comeon in, have a chat!
Website Suggestionsand Questions
Radio Repair corner
Helpful online tools
Androx's Corner
Radio modifications andInformation
Shortwave, Scanner ,CB, Ham radio pages
For Sale: Replica radiooperators tower's
My Radio Shack
links
software
My other Websites
Computer Problems
LOST WEBPAGES
For sale or Trade
The quickest and easiest way I have found to make a QUICK andEASY 10m rig.
There must be millions of the older 23 channel CBs that use the 12crystal synthesizer set-up with a 23 MHz oscillator and 14 MHzoscillator setup. Check "Garage Sales & Flea Markets" for thebargain rigs
In this rig, the 23MHz signal mixes with the 14MHz signal toproduce a signal in the 38MHz plus range.To receive, this 38MHz signal is mixed with the receive oscillatorsignal (11.730MHz) to have a signal that is 455KCs offset from theoperating frequency.Example… 23.290MHz mixes with 14.950MHz for the 38.240frequency and then mixed with 11.730 to get 26.510MHz …. This26.510 is .455 lower than 26.965MHz which is channel one..
To Transmit, this 38MHz signal is mixed with the transmit oscillatorsignal (11.275) to have a 26.965MHz operating signal.Example…. For channel 23…. 23.540 mixes with 14.990 to get a38.530MHz signal. The 38.530MHz signal is mixed with 11.275MHzfor a 27.255MHz transmit signal.
Now find a crystal from almost any 40 channel PLL controlledCB…… the reference frequency crystal is 10.240mhz (Most common….. almost universal use by manufacturers)...... actually, a10.180MHz or a 10.000MHz will work equally well...... it just causesthe beacon frequency to be a different channel to start at28.290MHz (with the 10.180MHz crystal... this starts at channel 19)...and (with the 10.000MHz crystal.... this starts at channel 5)
Substitute the 10.240MHz crystal for the 11.275MHz transmitoscillator crystal.. Now, channel 1 becomes a transmit frequency of28.000MHz. .Channel 10 becomes 28.110MHz.Channel 19 becomes 28.220MHzChannel 20 becomes 28.240MHzChannel 21 28.250MHzChannel 22 28.260MHzChannel 23 28.290MHz
With a little capacitance added .... the crystal will "bend" a fewHertz either way. In parallel the frequency goes down ... in series, itgoes up. I like to use a "trimmer" in series for frequency
convert a 23ch CB to 10m beacon transmitter http://radionut53.tripod.com/id477.html
1 de 2 08/06/2011 10:48
"tweaking"....... 10 KCs easy.
The CARRIER output should be about 2 Watts after the "cans" inthe transmit circuit are "tweaked" .....Do not adjust any of the"cans" except those that "follow" the TRANSMIT OSCILLATOR tothe output.
Typical adjustment locations
Currently the Ten meter "beacon band" is considered to be 28.175to 28.300MHzThe FCC rules only state that if the beacon is automaticallycontrolled… it must be 28.200 to 28.300MHz….. Please refer to acurrent listing of ten meter beacons to select a frequency.
A short piece of Co-Ax connected to a receiver tuned to 28 MHzfrequencies can be used as a "sniffer" when tweaking the"cans"..... watch the S meter and adjust the "cans" to the highestreading at the selected beacon frequency.
To transmit a CW signal, a person only needs to interrupt the PTTcircuit of an AM rig.There are many ways to "key" the PTT circuit……. Any memorykeyer …. Computers
convert a 23ch CB to 10m beacon transmitter http://radionut53.tripod.com/id477.html
2 de 2 08/06/2011 10:48
