jayer@hpcvia.CV.HP.COM (Jay_Reinhart) (06/01/90)
I am looking for sources for a good wireless FM transmitter that is fairly
low cost. I need one that is small enough to fit inside a motorcycle helmet. Or
if it is cheaper I could just run the mike into the helmet and carry the trans-
mitter.
Jay Reinhart
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The above and beyond are mine. I am not a lawyer therefore I do not represent
HP nor receive a lawyers salary. Nor do I represent myself in a court of law.
*******************************************************************************rpw3@rigden.wpd.sgi.com (Rob Warnock) (06/01/90)
In article <27510002@hpcvia.CV.HP.COM> jayer@hpcvia.CV.HP.COM (Jay_Reinhart) writes: +--------------- | I am looking for sources for a good wireless FM transmitter that is fairly | low cost. I need one that is small enough to fit inside a motorcycle helmet. | Or if it is cheaper I could just run the mike into the helmet and carry | the transmitter. +--------------- Radio-Shack has a new version of their 49 MHz walkie-talkie that uses a combined earplug/mic, the kind that picks up your voice *out* through your ear. The actual transceiver is in a little box that mounts on a belt clip. The wire between is also the antenna. These things are not particularly cheap -- ~$80/pair -- but work fairly well at free-space ranges up to 1/4 mile. Sould be ideal for a bike. If carefully you pick the channel number (A, B, etc.) printed on the box to be "A", it will interoperate with both of the older-styles: "bug ears" (like a telephone operators headset with a whip and a wire to a belt box), and the small hand-held box-with-shorty-whip style. -Rob ----- Rob Warnock, MS-9U/510 rpw3@sgi.com rpw3@pei.com Silicon Graphics, Inc. (415)335-1673 Protocol Engines, Inc. 2011 N. Shoreline Blvd. Mountain View, CA 94039-7311
root@ninja.dell.com (Randy Davis) (06/01/90)
In article <61340@sgi.sgi.com> rpw3@sgi.com (Rob Warnock) writes: |In article <27510002@hpcvia.CV.HP.COM> jayer@hpcvia.CV.HP.COM |(Jay_Reinhart) writes: |+--------------- || I am looking for sources for a good wireless FM transmitter that is fairly || low cost. I need one that is small enough to fit inside a motorcycle helmet. || Or if it is cheaper I could just run the mike into the helmet and carry || the transmitter. |+--------------- | |Radio-Shack has a new version of their 49 MHz walkie-talkie that uses a |combined earplug/mic, the kind that picks up your voice *out* through your |ear. The actual transceiver is in a little box that mounts on a belt clip. |The wire between is also the antenna. | |These things are not particularly cheap -- ~$80/pair -- but work fairly |well at free-space ranges up to 1/4 mile. Sould be ideal for a bike. (They are much cheaper elsewhere - around $65/pair at Sams Wholesale as I recall - usable, real-world range is much less than that also.) The consensus in rec.motorcycles seems to be that the combined mic/earphone units are totally unusable on a motorcycle. In addition, recent discussion from those that use them indicate that the range on the 49MHz FM units are totally unsuitable in motorcycle applications in general. In particular, the VOX (voice-activated mics) are pretty useless in the high-ambient-noise enviroment of a motorcycle, primarily due to wind noise. The only exception to this sometimes is use on fully (and I mean completely) faired mototcycles like the long-distance luxury tourers. As an alternative, many people have spoken highly of using simple CB units on a motorcycle. I am in the process of fabricating a headset to build into my helmet, by mating a new mic and headphone arrangement to a matching mic plug and external speaker plug on the $39 Uniden CB radios I bought at Service Merchandise. By the time I finish buying the parts, the antenna, etc.., including the tank bag for my wife's bike (to mount her CB in), the cost will have exceeded the cost of the FM units by quite a bit, yet I will have the advantage of longer range and many more channels, plus the ability to communicate with the more common CB radio crowd, if I so choose. For further opinions, perhaps a posting in rec.motorcycles would be more appropriate, or at least cross-posted there. Randy Davis UUCP: rjd@ninja.dell.com ZX-11 #00072 Pilot DoD #00013 --
darel@maccs.dcss.mcmaster.ca (Darel Mesher) (06/07/90)
In article <61340@sgi.sgi.com> rpw3@sgi.com (Rob Warnock) writes: >In article <27510002@hpcvia.CV.HP.COM> jayer@hpcvia.CV.HP.COM >(Jay_Reinhart) writes: >+--------------- >| I am looking for sources for a good wireless FM transmitter that is fairly >| low cost. I need one that is small enough to fit inside a motorcycle helmet. >| Or if it is cheaper I could just run the mike into the helmet and carry >| the transmitter. >+--------------- > >Radio-Shack has a new version of their 49 MHz walkie-talkie that uses a >combined earplug/mic, the kind that picks up your voice *out* through your >ear. The actual transceiver is in a little box that mounts on a belt clip. >The wire between is also the antenna. > I had to respond to this one..... don't buy these units with the interest of using them on motorcyles! i) the units are very susceptible to engine noise radiated at such close distances (ie. spark plugs only a few feet away) ii) the units require a separation between the two units for proper operation, the spurious radiation from the units themselves interfere with normal VOX operation. If both the driver and passenger are using the units and one unit xmits, the other unit will toggle into xmit mode ..therefore neither unit can receive, and they will remain in xmit mode until manually switched out of VOX. iii) Finally... you must also realize the there are a KaZillion Fisher Price baby monitors out there, each on 49Mhz and each broadcasting for miles and miles and miles..... Last year on a bike trip out east my wife and I were absolutely amazed at the conversations we were party to because of the RS headsets we were wearing. Every time we entered a city limits the VOX would kick in and then we would get to listen to crying, baby-talk, family fights...... I'll tell you, the FBI sure doesn't need to bug houses anymore- just use a baby-monitor-monitor! So, spend the little extra and buy headsets actually designed for motorcycle use! (as a side note, I immediately took the units apart to see if I could desensitive/detune the units for close proximity use to no avail; unmarked hybrid parts with few tunable components!) Darel -- ============================================================================= Darel Mesher Electrical and Computer Engineering McMaster University darel@maccs.dcss.mcmaster.ca
kline@ux1.cso.uiuc.edu (Charley Kline) (06/08/90)
darel@maccs.dcss.mcmaster.ca (Darel Mesher) writes: > iii) Finally... you must also realize the there are a KaZillion Fisher > Price baby monitors out there, each on 49Mhz and each broadcasting > for miles and miles and miles..... Last year on a bike trip out > east my wife and I were absolutely amazed at the conversations we > were party to because of the RS headsets we were wearing. Every time > we entered a city limits the VOX would kick in and then we would > get to listen to crying, baby-talk, family fights...... I'll tell > you, the FBI sure doesn't need to bug houses anymore- just use > a baby-monitor-monitor! I'm sayin'. At the little theatre I volunteer at they went through three or four sets of wireless intercoms for backstage communications and show calling until I convinced them that they were ALL on 49MHz and ALL would have the same terribly distracting squelch-breaks and babbling children. I just finished installing a wired intercom I designed (with the help of this newsgroup, I might add.. THANKS EVERYBODY.. wish you could see the program for our production of Noises Off.. "sci.electronics" gets an acknowledgement credit that I made them put in) which finally solved the problem once and for all. Out of curiosity, I drove around town one night with a scanner watching the 49MHz and thereabouts frequencies, and I made the same observation as Mr. Mesher did--there's a lot of fun things to listen to!! :) _____ Charley Kline Assistant Technical Director and Gadgeteer, the Celebration Company, Urbana IL. c-kline@uiuc.edu Six weeks and counting down.