Just add my 2 cents in here. I used to be an Amateur Radio operator, so the problem is SWR. This is the forward voltage vs. the reverse voltage down the antenna. SWR is a function of the wavelength (frequency) of the signal, and the length of the antenna. An SWR of 1:1 means that you have no signal returning to the transmitter. A 3:1 SWR is very bad, meaning you are getting more power returning to the transmitter than is going out. You can purchase a SWR meter at HAM stores. It may be a good idea to get the maximum signal out the antenna. Eric Hvinden- AME IMAGING -----Original Message----- From: Justin Crooks To: PICLIST@MITVMA.MIT.EDU Date: Thursday, March 26, 1998 4:19 PM Subject: Re: Programmer sold, RF freq's >Yeah, I experienced the same problemwith 418 MHz Abacoms. Which antenna >are you using? They >must be EXACTLY the right length for maximum range. (PIC driven, of course, >for picky PICLIST members). The whip antena gave us the best results. If >I remember right, 16.5 cm for 418MHz, 15.5 cm for 433MHz (1/4 wave, you can >do the math). Use a thick, straight piece of wire or something. We even >went so far as to use a digital caliper when cutting the antenna (with good >results. Of course, we were probably overly anal). Good luck!!! > >---------- >> From: John P. Leonard >> To: PICLIST@MITVMA.MIT.EDU >> Subject: Programmer sold, RF freq's >> Date: Thursday, March 26, 1998 7:55 AM >> >> Hey, I sold the programmer; thanks for the numerous offers. >> "Is he toilet-trained, union..." sounds like the frequent comments about >> drummers made on the bass players list group "The Bottom Line" but hey, >> not by me :) >> >> Please allow a brief [OT] excursion RE: 418MHz vs. 433MHz: >> >> I'm playing with the Lynx Tech. 418MHz eval. kit and a 433MHz pair from >> Abacom Tech. and have had serious difficulty achieving anywhere near the >> ranges claimed by either. The Lynx pair will barely reach 30-40 ft. out- >> doors in direct line-of-sight. (Spec. sheet says "...a highly reliable >RF >> link capable of transferring serial data at distances in excess of 300 >ft. >> is formed.") I'm awaiting a return call from Lynx's tech. support; I >MUST >> be doing SOMETHING wrong. >> >> If Bob Blick or anyone else would care to continue this discussion via >> private E-mail I am interested. (I know if it ain't PIC-PIC-PIC it'll >> piss somebody off; and don't want to see -SNIP-BITCH-SNIP- about it for >> the next week.) >> >> Yeh, I'm having a REALLY bad day, >> John >