Every store had at least one or two in stock. Check the local store. They can tell you how many are at which stores any where in the country. One of the guys at work wanted one after seeing mine and every store in town still had one except the store where she worked. stock number 22-306 John Ferrell wrote: > > Not on the web site... > I would have to take that one too! > > John Ferrell > 6241 Phillippi Rd > Julian NC 27283 > Phone: (336)685-9606 > Dixie Competition Products > NSRCA 479 AMA 4190 W8CCW > "My Competition is Not My Enemy" > > ----- Original Message ----- > From: "Larry Williams" > To: > Sent: Friday, August 10, 2001 7:55 PM > Subject: Re: [PIC]: Building a "counter" w/PIC16F628 > > > If you need a decent freq counter, check radio shack. They have on that is > discontinued and is now reduced down to $49.95. I bought one just because > it was cheap( even cheaper since my wife gets 25% off) and today it got its > first use on top of a 380 foot tower checking freqs in a tower top microwave > transceiver. Good to either 1.3 or 1.6 ghz. Don't remember for sure. Has > seperate switch position for ttl level / rf > > > > > > From: Dan Michaels > > > Date: 2001/08/10 Fri AM 11:44:40 EDT > > > To: PICLIST@MITVMA.MIT.EDU > > > Subject: Re: [PIC]: Building a "counter" w/PIC16F628 > > > > > > Mike, > > > > > > The problem here is you are not simply dipping a grid, you > > > are interfacing a 200+ Mhz tiny RF signal to a digital chip. > > > That is why I mentioned the real crux of this project is in > > > "RF design/layout/matching/amplification/sensing/etc" - taking > > > that tiny signal and converting successfully to 0-5v. > > > > > > Once you have picked up and amplified the "sine", then you > > > can use an analog prescaler and/or schmitt trigger to square > > > up for presentation to the PIC. The PIC can probably accept a > > > sinewave ok, as long as it is large enough [about +/-2v], shifted > > > into the range 0-5v, and slews fast enough so that noise doesn't > > > cause false counts. > > > > > > AN592 talks about using Timer0 of the '84 for counting. I mentioned > > > it mainly for reference. The '628 is probably too new to find much > > > specifically about using it. However, the Timer1 module is the same > > > as on the '74/'76/'77/'874/'876/'877, so you can look at those > > > chips. > > > > > > Also, I don't know anything about the el cheapo programmer and > > > the '628. Again, the '628 is so new, not everything out there > > > supports it. > > > > > > - dan > > > =============== > > > > > > > > > At 10:43 PM 8/9/01 -0000, you wrote: > > > >Dan, > > > > On the oscillator part of the circuit, it is too easy actually. > The > > > >user of the Grid Dip Oscillator adjusts a knob to vary the frequency of > the > > > >circuit. As the frequency is adjusted the current going through the > meter > > > >will change if it matches the resonant circuit by dipping. These hand > held > > > >pieces of test equipment have been around for over 60years to my > knowledge > > > >and are beautiful in their simplicity. They origionally consisted of a > > > >single vacuum tube that had the plug in coils. The tricky part of the > > > >origional design was that the coils had to be wound so that the readout > on > > > >the printed dial matched the actual frequency within reason. In this > > > >application, that is totally unimportant as the digital frequency > counter > > > >does the job. Therefore, I can use handwound coils that vary > considerably > > > >from each unit produced just as long as the frequency readout is > correct, > > > >everything is A OK. > > > > A 180mhz digital readout would really be perfect for me. > > > > > > > >1st question-do you think I'll be able to use the sine wave into the > > > >counter, or would I need to "shape it" for the PIC?? > > > > > > > >2nd question-from what you described origionally, the 74AC74 would be > great. > > > >I'm not looking for 1hz resolution or anything. As a matter of fact > 10khz > > > >or 1Khz resolution would be great! Do you agree, or do you still feel > that a > > > >prescaler is better? > > > > > > > >3rd question-is the AN592 related to the 16F84, or PIC16F628? > > > > > > > >4th question-do you think the "el cheapo" programmer from Myke Predko's > book > > > >will work with the PIC16F628 if I go that route? > > > > > > > >Thanks again/regards, > > > >Mike > > > >----- Original Message ----- > > > >From: "Dan Michaels" > > > >To: "Mike Kendall" > > > >Sent: Friday, August 10, 2001 3:15 AM > > > >Subject: Re: [PIC]: Building a "counter" w/PIC16F628 > > > > > > > > > > > >> Mike Kendall wrote: > > > >> >Dan, > > > >> > Yes, I will be counting analog signals out of an oscillator > circuit. > > > >> >These will/should be a clean sine wave. I will describe my project. > I > > > >was > > > >> >disgusted with the high price of simple analog grid dip oscillators. > The > > > >3 > > > >> >and 4 decade old units were going quite high and the new units were > > > >around > > > >> >100 bucks for an analog meter face type unit with little accuracy. > > > >> ........... > > > >> Ideally, the circuit > > > >> >will work up to 250mhz, but up to 180mhz would be outstanding as it > would > > > >> >cover the marine band, 2meter ham band and down to hopefully 1.8 mhz > > > >(even > > > >> >lower would be better). > > > >> .......... > > > >> > > > >> > > > >> Mike, from what you describe, the PIC part of this should be fairly > > > >> easy. Check the appnote, AN592, that I mentioned for prelim info. > > > >> Other Mchp appnotes discuss interfacing LEDs/LCDs - AN590, AN529, > > > >> AN563. > > > >> > > > >> The harder part looks like the analog front end to 250 Mhz. Does > > > >> sound like a prescaler chip is in order - plus of course correct > > > >> RF design/layout/matching/amplification/sensing/etc. This part > > > >> requires a lot more savvy, I think, than writing a few lines of > > > >> PIC code. A 16:1 or 32:1 prescaler should put you into the correct > > > >> range for the PIC. > > > >> > > > >> good luck, > > > >> - dan > > > >> ============= > > > >> > > > > > > > > > > > > > > > > > > -- > > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > > > > > > > > > > > -- > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > > > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics