| Author |
Message |
    
Mayor513
Junior Member
Username: Mayor513
Post Number: 23
Registered: 3-2002
| | Posted on Saturday, June 11, 2005 - 10:12 pm: | 
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Hi, all. I have a President P400 (same as the Uniden Washington) that has the MB8719 chip, and a PC385ag circuit board in it. I bought it when I was in High School (1990 or so) and had an Expo Kit put in it, and it currently goes from about 26.53 - 27.845Mhz. I am now wanting to convert it to a segment of the 10 meter band. As the radio is right now, it has a 1.3 Mhz bandwidth. SO, is there a way to make it go from about 28.000 to 29.300? What is involved to do this? If the radio cannot be converted that far, is it still possible to at least have coverage from about 28.300 to 29.200? That way, I can use SSB at the bottom end and the AM mode from 29.000-29.200. I am assuming the first step is to change out the 11 Mhz crystal, but I know it can't be THAT easy, as it will probably start losing more power the higher I go. Any help will be appreciated. Thanks! |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 385
Registered: 6-2004
| | Posted on Saturday, June 11, 2005 - 10:37 pm: |
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Actually, it is that easy depending on how your Expo kit works. If it's a crystal switch you'll have to buy new crystals, but if it's some kind of binary programmer for the PLL you can just calculate the frequency of the new crystal and once you've got it installed, do a complete alignment on the radio for the new frequency range. |
Mayor513
Junior Member
Username: Mayor513
Post Number: 24
Registered: 3-2002
| | Posted on Sunday, June 12, 2005 - 3:08 pm: |
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Thanks for info. Yeah, it's a three position crystal switch. If I can figure out what frequency crystal to get, I might just use one crystal to save some money (I figure they are about $20 each?). By figuring out the proper frequency of crystal, maybe I can have coverage from 28.300 to 28.700. I already have a Yaesu FT-100 HF radio, but figured I might do some experimenting, haha. The radio is in another town right now, otherwise, I would be able to give more information (IE, frequencies of the crystals, etc.) Thanks. |
Bruce
Senior Member
Username: Bruce
Post Number: 2854
Registered: 9-2003
| | Posted on Monday, June 13, 2005 - 7:16 am: |
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You have a FT-100 or 100D ? And does it have the upgrades done like the over size fan?
 |
Mayor513
Junior Member
Username: Mayor513
Post Number: 25
Registered: 3-2002
| | Posted on Monday, June 13, 2005 - 12:01 pm: |
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Hi, Bruce. I just have the regular FT-100, non D model. The only mods I have done so far is the fan mod, and the microphone mod. I am now starting to have problems with the oscillations and high SWR readings. I like the radio, but I think that this will be my last "all in one" small radio. It's handy having all bands inside one radio, but everything is so tightly packed in there, it gets very hot on long keydowns at 50% power. For the money, these type of radios are hard to beat, but next time, I think I will just get an ICOM IC-718 HF rig, and an ICOM IC-910H 2 meter/70cm/1240 rig. |
Bruce
Senior Member
Username: Bruce
Post Number: 2855
Registered: 9-2003
| | Posted on Monday, June 13, 2005 - 2:13 pm: |
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there are mods for the problems on the internet look up the FT-100 users group on yahoo |
Mayor513
Junior Member
Username: Mayor513
Post Number: 26
Registered: 3-2002
| | Posted on Wednesday, June 15, 2005 - 8:47 pm: |
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Hi. Does anyone know what crystal I would need to move the frequency range from the Citizen's Band to 28.3-28.7? I don't have the radio at my current location, but I think the 11Mhz crystal is 11.1125? For example, if I have a 11.1125Mhz crystal, but want to move the frequency range of the radio UP 1.3 mhz (from 27.000mhz to 28.300mhz) would I then have to purchase a crystal that is 12.4125? I have no idea how any of this works, so if I am wrong, please tell me. Any tips would be helpful...thanks.
Adam |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 404
Registered: 6-2004
| | Posted on Thursday, June 16, 2005 - 7:54 am: |
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You'll want CH 1 to be at 28.305MHz so you can slide down 5KHz with the clarifier to 28.300MHz.
28.305MHz - 26.965MHz = 1.34MHz
11.1125MHz + 1.34MHz = 12.4525MHz
So the new crystal should be 12.4525MHz.
Now that'll give you a range from 28.305MHz to 28.745MHz. |
Blaacksheep
New member
Username: Blaacksheep
Post Number: 1
Registered: 7-2005
| | Posted on Saturday, July 09, 2005 - 5:13 am: |
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Actually, that crystal is tripled in the loop mixer to a frequencty of 33.3375. That freq, plus 1.34 MHz = 34.6775. Divide that freq by 3 to get 11.55916 for your new crystal. Be aware that the VCO in that radio will cover a maximum range of about 1.3 MHz and the TX mixer stage is pretty tight, so don't expect your lowers and 10 meters to both work without serious modifications. |
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