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Message |
    
Kc8gpd
Junior Member
Username: Kc8gpd
Post Number: 24
Registered: 2-2004
| | Posted on Friday, February 12, 2010 - 1:26 pm: | 
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here is my thought on how to implement this...
TX site:
Feq: 27.315
TPO: 4 Watts
Mode: AM
Antenna: Custom Dual 4 Bay Folded Dipole
Filter: Bp: 27.315 Br: 27.965
Coax: Andrew 1 Inch Hardline
Controller: Rack Mount Custom Controller, and Receive Voter
Transmitter: Cutom Built Crystal Controlled 4 Watt AM Transmitter
Rx Site:
Freq: 27.965
Mode: AM
Antenna: Custom Dual 2 Bay Folded Dipole
Filter: Bp: 27.965 Br: 27.315
PreAmp: Custom Built Single Freq. Tower Mounted Pre Amp.
Receiver: Custom Built Crystal Controlled AM Receiver
Coax: Andrew 1 inch hardline
Tx/Rx Site Seperation: 1 Mile Minimum
Tx/Rx site Linking: Telco Wireline
Yes I put a lot of thought into it 
I come up with all these wacky idea's, but never get around to implementing them.
the question has been asked on numerous cb forums over the years, so i finally decided to put some thought into it and come up with a solution.
i posed the question on another forum and the above is the culmination of our brain storming.
if someone takes the idea and runs with it please let me know how it works out and what mods you make to the design.
i also found out the history behind the legendary CB repeater. it apparently was done in the USA in Boston, MA Some 40 years ago and had a 10-15 mile Range.
Rev. Robert P. Chrysafis
Universal Life Ministries (ULC)
http://www.ulc.org
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2ec837
Intermediate Member
Username: 2ec837
Post Number: 139
Registered: 12-2001
| | Posted on Saturday, February 13, 2010 - 12:57 pm: |
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I would suggest using CTCSS on both the input and output, but I can't think of any "type accepted" or "FCC certified" CB radios being manufactured for use in the USA for years. |
Tech237
Moderator
Username: Tech237
Post Number: 1299
Registered: 4-2004
| | Posted on Sunday, February 14, 2010 - 8:57 am: |
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Apart from 2ec837's comments an 11m Repeater is also illegal.
Right now I am designing a 10m one pretty similar to what you describe EXCEPT single site. We are currently playing with filters made from 75ohm 5/8" hardline (hey I get it free from work)and have almost enough isolation to make it work.
Our test rigs are my IC-706 as TX (on 100w) and my HTX-10 on receive. Once the bugs are worked out, I'll modifiy a lowband commercial radio for the permanent installation.
Tech237
N7AUS
Chipmonks roasting on an open fire
Hot sauce dripping from their toes.
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Kc8gpd
Junior Member
Username: Kc8gpd
Post Number: 25
Registered: 2-2004
| | Posted on Monday, February 15, 2010 - 12:23 pm: |
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I am re-thinking the design. about 10 watts TPO PEP at 100% duty into a BpBr duplexer offering about 60db isolation with about 3db insertion loss. still using 1/2 inch hardline replace antenna with single a 1/4 wave folded vertical ground plane similar to the ones used in commercial low band service or a custom 2 bay folded 1/2 wave dipole. Still AM mode. Output on Ch 31 input on Ch 5. DTMF Decoder to open/close squelch. linear preamp on receive side of duplexer.
no cares about the legalities on the regular 40 channels anymore. i think as long as whatever goes on is contained between 26.965 and 27.405 the FCC just does not bother. if you notice all the CB enforcement almost always has to do with CB shops selling linears or out of band operation or interference.
this is a project born out of boredom and wanting to do something unusual.
Rev. Robert P. Chrysafis
Universal Life Ministries (ULC)
http://www.ulc.org
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Kc8gpd
Junior Member
Username: Kc8gpd
Post Number: 26
Registered: 2-2004
| | Posted on Monday, February 15, 2010 - 12:25 pm: |
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[quote]Our test rigs are my IC-706 as TX (on 100w) and my HTX-10 on receive. Once the bugs are worked out, I'll modifiy a lowband commercial radio for the permanent installation.[/quote]
going to run a modified syntor x?
Rev. Robert P. Chrysafis
Universal Life Ministries (ULC)
http://www.ulc.org
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Tech237
Moderator
Username: Tech237
Post Number: 1305
Registered: 4-2004
| | Posted on Tuesday, February 16, 2010 - 9:42 am: |
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most likely if I can find one..
Tech237
N7AUS
Chipmonks roasting on an open fire
Hot sauce dripping from their toes.
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Kc8gpd
Junior Member
Username: Kc8gpd
Post Number: 27
Registered: 2-2004
| | Posted on Tuesday, February 16, 2010 - 6:25 pm: |
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you can find them all over ebay dirt cheap and usually dirt cheap at most hamfests.
Rev. Robert P. Chrysafis
Universal Life Ministries (ULC)
http://www.ulc.org
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