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Message |
    
Adk46er
New member
Username: Adk46er
Post Number: 1
Registered: 10-2020
| | Posted on Thursday, October 22, 2020 - 3:01 pm: | 
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Hi Guys
My first post as a new member. I have been a licensed Ham since 1960, with the Call Sign KS2K.
Its my desire to convert a CB Radio to 10 Meters and idealy remove access to all of the CB frequencies which I don’t need. I want to use this to learn more about total frequency/band conversion, conversion from AM to FM or SSB, and in the end up with a useful radio for my truck and camp.
I have done a lot of reading on the web. It appears that some CB’s like Realistic TCR-458 and
Cobra 139xls are a breeze to convert to 10 meters, others are a Maybe ? and some are not convertible . Thus begins the saga. Not wanting to reinvent the wheel if not need be, I como to the forum members for advice and experience.
I was walking around a huge Yard Sale and one person had a table full of CB sets, most with names I have never heard of before. However, he did have a Like New In the Box Cobra 25 WX ST Sound Tracker hooked up on a battery that also has the NOAA Weather Channels with are NB FM on 162.xx
It played nice. I mentioned my desire to convert to 10 meters. He said I have just what you need,
A Expo 100 Expander Kit S +- (no manual or paper work) which is made for the Cobra 25.
So I bought it for short buck, less than 2 lunches at Burger King. I get home surf the web and find that the Expo 100 Expander Kit S+- only modifies the CB Frequency range to 26.515 MHz to 27.855 MHz. No good short of 10 meters. I want to cover 10 meters 28.100 MHz to 29.700 MHz. Now What ?
I did find a post on THIS FORUM made back on March 21, 2005 at 4:21 PM his handle was Kilowatt and a member by the handle of Tech 808 also posted. This is a short copy of what was posted;
Those Expo 100 kits are a good way to put a CB on 10 meters, too. You just chunk the crystals that come with it and replace them with 3 that are cut to put you on 10 meters.
I've got a Grant (original) on 10 meters using that method, now. I can cover all of the SSB areas and the AM portion around 29.000 MC.
Anyone know what the 3 new crystal frequencies must be, and their location on the Expo 100 board ? I tried to contact Kilowatt who also appears to be a Ham with the call sign AC5CH, but no response, maybe he is a SK ?
Sorry for the length, but you need to know all the info I have
Thank You
KS2K |
Tech833
Moderator
Username: Tech833
Post Number: 2476
Registered: 8-2002
| | Posted on Wednesday, November 04, 2020 - 2:42 pm: |
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Greetings KS2K!
The Cobra 25 went through several revisions. Depending on your revision, the PLL chip may not go to 10m. An external VFO would fix that.
I'm not familiar with the Expo 100 Expander or any of the devises similar. My guess is it allows you to add a different crystal to the PLL circuit to skew it elsewhere.
If you are dead set on converting a CB radio to the 10m ham band, keep an eye open for a crystal type set, like one of the old 23 channel radios. Those are super simple to convert by simply changing crystals. Once you include a PLL integrated circuit, things get complicated to drag the operating frequency so far away from 27 MHz.
73!
Your radio 'Mythbuster' since 1998
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Wookie
Junior Member
Username: Wookie
Post Number: 10
Registered: 2-2021
| | Posted on Tuesday, May 11, 2021 - 7:57 pm: |
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open the radio up and let us know the PLL type the radio uses as i may be able to help with an easier way good luck. |
Charliebrown
Advanced Member
Username: Charliebrown
Post Number: 750
Registered: 10-2002
| | Posted on Friday, May 14, 2021 - 10:46 pm: |
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Why not just get an RCI 2950dx that will do 10 and 12 meter plus 11 meter if you want or one of the other brand radio's that do 10 and 12 meter ? I know they cost more than your expander but you do not have to go through all trouble of the conversion of the expander. Like many other's on here thanks to the TECHS here we have done a lot of conversions also. It is fun to do. By the way I am a ham operator as well and have been in the hobby for over 53 years. You can look me up on this site if you want to see my info. |
Watt
Member
Username: Watt
Post Number: 87
Registered: 1-2004
| | Posted on Sunday, May 23, 2021 - 12:19 pm: |
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Some people like to warm up the soldering iron and not just buy a radio.
DX is the next best thing to being there.
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Charliebrown
Advanced Member
Username: Charliebrown
Post Number: 754
Registered: 10-2002
| | Posted on Thursday, May 27, 2021 - 2:24 am: |
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True, In the past 50 years or so I have done many myself. However with today's SMT (SURFACE MOUNT TECHNOLOGY ) board's it is getting much , much smaller and harder to work on. I have done a few repair's on mine and if it would get any smaller I will just leave it alone and buy new. |
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