| Author |
Message |
    
Swamper
| | Posted on Thursday, January 16, 2003 - 4:22 pm: | 
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I just bought a used cobra 2000 and i have found most of the extra channels.It seems to go up to 28.0449 and down to 26.2149 using the anl~nb~and cb ~pa switches.My question is i cant seem to find any channels in between 26.7650 being the higest lower i found and 26.9650 channel 1.Does this radio just not cover them or am i just not finding them????....thanks any help would be great!  |
307
| | Posted on Friday, January 17, 2003 - 9:10 am: |
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That radio "if pins 10 and 11" on the PLL are used will cover channel 15 (26.815) to channel 40 (28.045) in 3 different positions. You can buy an "Expo L Kit" and get 3 bands of 40 each or an EPROM can be added for 400 channels. This is expensive and really not worth it.
307 |
Glassbysam
| | Posted on Friday, January 17, 2003 - 10:13 pm: |
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307 ,... who would one buy an "Expo L Kit " from? I would like to put one in a cobra 148F GTL
thanks
sam |
Swamper
| | Posted on Sunday, January 19, 2003 - 12:19 am: |
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WHERE CAN I GET AN EXPO KIT?.AND IF I PUT IT IN MY COBRA 2000 HOW LOW AND HIGH WILL MAY RADIO GO??THANKS! |
CM 3885
| | Posted on Monday, January 20, 2003 - 12:59 am: |
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307
Would a digiscan 400 work on a 8719 PLL in a cobra 142 GTL? |
2600
| | Posted on Monday, January 20, 2003 - 2:38 am: |
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Hey, CM 3885, is the Digiscan "400" the one with the ten-conductor flat cable, or the one with two coax cables, a red and a black wire?
The flat-cable version is specific to the PLL chip they set it up for. All it does is take the place of the channel switch, feeding your original PLL chip in its place. The one I remember that matched the old uPD858 chip was called "Digi-Tune". That one WON'T work on a 8719. The binary codes are completely different. The last one I saw on a 8719 chip had been removed from its case, and installed inside the radio, behind the clock window.
The one with the two coax cables has its own PLL chip inside, and bypasses the 8719 in the radio. Some folks take the original PLL chip out of the radio, others just unhook the "out-of-lock" detector and tuning voltage, leaving it in place.
The "Expo 100" kits twenty years ago only went up and down 44 channels. This created a one-channel "overlap" on the two new bands. Channel "one" on the uppers was channel 40.... again. Channel "40" on the lowers was channel 1. Since those days, "export" radios became popular. They use a 45-channel-per-band scheme that makes "40" on the lowers one channel below channel 1. No overlap. Go up one band above and channel 1 is now channel 41. Later Expo kits were made with this scheme, and the channel-switch numbers on an Expo-converted CB radio would agree with a Galaxy/Connex/Superstar channel number one band below and one band above. Some of the later "45-channel" kits were made with the old "44-channel" crystals in them. Capacitors were added to make the old crystals "stretch" one more channel up or down. Some of those just weren't very stable at all. Eventually they ran out of the "44-channel" crystals. Newer ones have crystals that were made for the "45-channel" jump. I wonder how much of the reputation for frequency drift is due to these "in-between" kits? My usual advice is that if you run mostly AM, the Expo kit is plenty stable enough. If you run SSB a lot, you may be disappointed with the stability in a mobile radio. Since a base station isn't subject to the temperature extremes of a mobile installation, the drift from an Expo kit may not be enough to be annoying.
Where to get one? That's a sticky subject. All the suppliers that I know also sell radios. Copper doesn't encourage posting links to competitors' web pages. Can't say I blame them. They ARE paying the bills to run this forum, after all. Seems fair enough to me.
Private e-mail with a link to one of these outfits only works if your e-mail addy is available.
73 |
Freebird
| | Posted on Tuesday, January 21, 2003 - 2:22 am: |
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i have a cobra 2000 and it goes down to 26.1750 that the lowest greq i can find on it.will someone e mail me about the expo kit. |
CM 3885
| | Posted on Tuesday, January 21, 2003 - 6:38 am: |
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2600
Look in your email i sent you a message on the digiscan... |
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