Home |
Search |
Today's Posts |
#4
|
|||
|
|||
tirebouchon69 wrote:
Hi, I want to modify an old ICOM IC-22s vhf radio for APRS at 144.390 MHz. I already made the 10 KHz step modification, and now I need to make it cover the lower part of the band, and this is where I get a problem: If I set binary code "0" on diode matrix, I should get 144.390 MHz exactly, but the VCO doesn't work at this low frequency (even if indector vco is re-tuned). I see 2 possibilities: 1- Change X2 crystal 44.56333 MHz for a lower crystal. For exemple, a 44.250 MHz would make the rig start at 143.450 MHz, and binary code "94" would generate 144.390 APRS frequency. Any crystal between 44.0 & 44.5 MHz would be fine. Where could I find such a crystal? (Digi-Key has nothing around 44.0 to 44.5 MHz Xtals) 2- Modify VCO circuit to make it work lower (changing D3 varicap, C40 or L7 probably?). Did someone try this before? Thank you in advance. ------------------------------------------- Daniel VE2BAP Montréal (Roxboro), Québec, Canada It's been a while, but I'm sure I didn't change any xtals. mike -- Return address is VALID. Bunch of stuff For Sale and Wanted at the link below. Toshiba & Compaq LiIon Batteries, Test Equipment Honda CB-125S $800 in PDX Yaesu FTV901R Transverter, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Icom IC-4AT operation? | Equipment | |||
"Remote Base" operation with the Kenwood TH-F6A (was: "Remote Base" operation with Icom IC-2720H) | Equipment | |||
"Remote Base" operation with the Kenwood TH-F6A (was: "Remote Base" operation with Icom IC-2720H) | Equipment | |||
"Remote Base" operation with Icom IC-2720H | Equipment | |||
"Remote Base" operation with Icom IC-2720H | Equipment |