Copper Talk » Ask The Tech » Radio's Mobile » Archived Messages » 307 i need your help!!!! need double lows in my 29 ltd, and 148 gtl « Previous Next »

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chode
Posted on Tuesday, August 21, 2001 - 4:00 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

how can i do this? do i have to have a kit, or can i jump the chip, or is there any way i can do this myself. any help would be deeply appreciated.
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307 (307)
Posted on Tuesday, August 21, 2001 - 12:42 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Well , chode , The 148 is easy , the 29..thats another story. If you look on the PLL programming pins on the 148 you will see that the LSB (least significant bit) can be changed as well as about 5 bits towards the MSB (most significant bit). By pulling the bit up with 5 volts or grounding it through 1K ohms , you change the programming. The "N" if I am correct starts about N=128 , so in theory if the VCO will track it will go all the way down 128 Channels. The nice thing about the MB8719 Chip is that you will run out af VCO Bandwidth before ever meeting the band edges. Hope this helps...
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chode
Posted on Tuesday, August 21, 2001 - 11:53 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

what? it doesnt help me a lot because i am semi radio smart operator. in other words, do i need a kit? can i jump the chip, or how do i do it? i have a knack for soldering, so if you can explain it in more simple terms, i can get it done. i hear your the man, so help me be less stupid. my father, before he died, said put extra channels in this thing for me. i never got to do it before that happened. i have a 29 ltd classic that he had too. he loved the lower frequencies. the 148 is the one i relly want to put the channels in. its a thing that somehow i must figure out how to do. e mail me if you have to if it is too complicated to explain here
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307 (307)
Posted on Wednesday, August 22, 2001 - 6:25 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

There are kits made by a company called "Card Kits" that will enable more range. You can look around on ebay for one , I have seen them there for a long time. You could also change the 11.325 crystal in the 148 to 11.125 to go lower. You can go lower by manipulating the programming pins. The kit for the 148 is an EXPO KIT "L".
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bluedog
Posted on Wednesday, August 22, 2001 - 10:29 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

What can you do to expand the MB8719 to go a full 40 channels lower? I know you can put an L kit in it but i want to stay away from that.
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307 (307)
Posted on Thursday, August 23, 2001 - 7:05 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ground pin 10 , and/or pin 11 on the MB8719. 10 is low , 11 is high , 10 and 11 is super high. Frequency range 26.815 (channel 15) to 28.045 (channel 40)
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bluedog
Posted on Thursday, August 23, 2001 - 12:31 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ok appreciate it! Is their anyway to get lower than 26.815? Like for instance 26.685.
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chode
Posted on Thursday, August 23, 2001 - 11:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

do i need two kits? how do you ground the pins. i need 26.065. if i can get that channel, i would be pleased. double low is what i need. new to webtv, wouldnt have the slightest clue on how to get to e bay. i can get the crystals at radio shack. can you e mail me with some info on how to do this project?

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