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Title: Hard Rock Heavy?? Teknuckle Qvezteeon! Post by: WBear2GCR on March 15, 2008, 11:14:33 AM I have a continuing Teknuckle draggin' qvezteeon... still.
I confess I am too lazy, busy and impatient to wade through all the stuff on these SRL v6.0 posts and websites to figure out the answer, ok? SO, is anyone here able to explain what the issue is with the center frequency and the xtal frequency for the radio?? I suspect it has something to do with the direct conversion part, but that only dimly lights neurons, insufficient for any real insights. FYI, I broke down and bought two of the suckers for IFfy use... so I'm in that far now... _-_-Willie Bought Two Grey Car Radios Title: Re: Hard Rock Heavy?? Teknuckle Qvezteeon! Post by: WA1GFZ on March 15, 2008, 03:29:27 PM You don't want zero at the center of your IF because there is a lot of noise there. I used a color burst crystal divided by 8 for 455 kHz IF putting zero at 7.625 KHz away.
Title: Re: Hard Rock Heavy?? Teknuckle Qvezteeon! Post by: WBear2GCR on March 15, 2008, 10:33:31 PM Soooo... are we saying then that for my R-388 with a 500kHz IF, that I want something like a 3.990Mhz xtal in the divide by 8 position? And I guess I can scarf up an old TV somewhere and find a color burst xtal... somehow. Ya know, people always say, "what are you keeping that old junk for[/u]"?? Well, this here pile-o-junk TV I'm gonna keep for the next 25 years or so, because one day electronics will be so small that you need a microscope to see the parts, and I'll need this stupid old color burst crystal to run a thing called a software controlled receiver that is the size of a saltine cracker...! (don't think I have any old TV chassis hanging around tho'... time to keep a keen eye out in the streets of the city of smAlbany... and double check the plastic parts drawer with xtals in it in case I clipped one 35 years ago and stuck it there... ::) ) Phew... wacky ain't it?? _-_-Wacky Bear Two Gets Computer Radio Title: Re: Hard Rock Heavy?? Teknuckle Qvezteeon! Post by: KF1Z on March 18, 2008, 01:16:39 PM Colorburst is what... 3.579mhz?
Probably too far off for 500khz IF... Divid by 8 is 447.4khz.... 500 minus 447.4= 52.6khz I'd go with something closer to 3.9mhz Title: Re: Hard Rock Heavy?? Teknuckle Qvezteeon! Post by: k4kyv on March 18, 2008, 01:35:38 PM And I guess I can scarf up an old TV somewhere and find a color burst xtal... somehow. Ya know, people always say, "what are you keeping that old junk for"?? Well, this here pile-o-junk TV I'm gonna keep for the next 25 years or so, because one day electronics will be so small that you need a microscope to see the parts, and I'll need this stupid old color burst crystal to run a thing called a software controlled receiver that is the size of a saltine cracker...! (don't think I have any old TV chassis hanging around tho'... time to keep a keen eye out in the streets of the city of smAlbany... and double check the plastic parts drawer with xtals in it in case I clipped one 35 years ago and stuck it there... I save every salvageable resistor, capacitor and other component that I even think I could possibly ever use, from anything I discard that uses point-to-point wiring. I also save old PC board scrap with reusable through-the-hole mounted components, whenever it looks like the stuff on it might be worth the space it takes up in the scrap box. With the advent of SMT and custom built IC chips, I can foresee the day in the not-to-distant future when discrete resistors and capacitors with wire leads will be as unobtainium as newly-manufactured vacuum tubes are to-day. |