I suspect your rocket is too small to for a patch antenna at the frequency these use. http://linux.students.engr.scu.edu/~bhorwath/presentations/Microstrip%20Patch%20Antenna%20Design.pdf
Joe On Fri, May 31, 2013 at 7:45 PM, Peter Hackett < [email protected]> wrote: > RE copper tape patch antenna: > > "Tell me more" :-) > > Specifically, how do you attach (say) a sma cable to the the copper tape? > And would I just tape 7" of the copper tape to the inside of the altimeter > bay? > > I guess I can figure this out with a bit of web surfing, but ... > > Is "Copper tape" something that is sticky like masking, er I mean rocket > tape > or is it more like cassette tape (copper on some sort of plastic film?) > > BTW love the pics of "Behemoth Bertha" rocket on your Google+ page > > Peter "A 'real' rocket would be fun" Hackett > > > On Fri, May 31, 2013 at 1:53 PM, Joe Zawodny <[email protected]> wrote: > >> Why not consider building a patch antenna out of the copper tape that >> hobbyists use in making stained glass. Patch antennae are what they use on >> "real" rockets. >> >> Joe Z >> >> >> On Fri, May 31, 2013 at 4:42 PM, Peter Hackett < >> [email protected]> wrote: >> >>> Casey and Bdale, thanks for the info! >>> >>> RE " ... when another newbie ham asked a similar question" >>> :-) you! >>> >>> Ok, I think I understand most everything. >>> >>> I did some more poking around (Casey's thread and a little Googling) >>> >>> Which got me to thinking about moving the altimeter from rocket to >>> rocket. >>> >>> I found a web page which seemed to suggest I could strip off (in my >>> case) ~ 7" >>> of the outer casing and outer conduct of a coax cable to form the >>> equivalent of >>> a 7" wire antenna. Does that sound right? >>> >>> Give that it is true (works reasonably well) I was thinking I could buy >>> a (say) 5ft >>> sma male to <anyConnector> coax cable cut off the <anyConnector> end, >>> drill a cable diameter hole in the "main" side of the altimeter bay >>> thread the cable >>> through leaving enough slack to easily connect the sma male connector to >>> the >>> TeleMetrum. I would then epoxy the cable as it passes from the inside to >>> the >>> outside of altimeter bay. Then I would cut the cable to (say) 8" long on >>> the outside >>> of the altimeter bay and strip 7" of the outer case and out conductor to >>> form the >>> wire antenna. >>> >>> *Seems* like it should work. Thoughts? >>> >>> This seems like it would be a good solution because I could install a >>> cable/antenna >>> in each rocket for the price of a sma male to xx cable (~$10) >>> >>> >>> >>> On Thu, May 30, 2013 at 9:30 PM, Bdale Garbee <[email protected]> wrote: >>> >>>> Peter Hackett <[email protected]> writes: >>>> >>>> > Can I just bend the whip antenna into a horse-shoe shape to get it to >>>> fit >>>> > into the altimeter bay? (I guess the really question is "Will this >>>> > significantly compromise the performance of the antenna?") And if it >>>> > is "a bad idea" what should I do? >>>> >>>> It's a bad idea for two reasons. One is that it'll dramatically impact >>>> the radiation pattern, as you surmise. The second is that doing that >>>> will put strain on the SMA connector's attachment to the board, which >>>> isn't a good idea. I've had to repair boards that had the SMA damaged >>>> or sheared off because of loads put on the connector by such an antenna >>>> setup... sadly, one was one of my own boards that I stuffed in a 54mm >>>> airframe in a hurry at a launch a couple of years ago .. /o\ >>>> >>>> > My first thought was to find a short SMA male to SMA female cable so >>>> that >>>> > the whip antenna can be straight. Is this "a good idea"? (necessary?, >>>> > etc) >>>> >>>> That's a better plan. >>>> >>>> > Next: in poking around the Altus Metrum and gag.com web sites while >>>> > researching about my altimeter question, I saw a link to a "SMA To BNC >>>> > adapter" on the Teledongle page. >>>> > >>>> > I bought an Arrow II Hand Held Portable Antenna 440-3 and in looking >>>> more >>>> > closely at the product description page, it looks like it has a BNC >>>> > connector. >>>> > >>>> > So it looks like I'll need to get either the SMA to BNC adapter or >>>> get a >>>> > coax cable with a male SMA connector on one end and a male BNC >>>> > connector on the other. Have I got that right? >>>> >>>> Yes. >>>> >>>> > If so, any recommendations? >>>> >>>> Ok. The SMA-BNC adapter is the optimal way to attach a TeleDongle to an >>>> Arrow antenna. It puts the receiver as close to the antenna feed point >>>> as possible, which minimizes the loss between the antenna and the >>>> receiver, giving you the best possible system noise temperature. >>>> >>>> On the rocket end, I really prefer the wire whip. The only reason to >>>> use an SMA is if you're installing the board in something like an >>>> aluminum or carbon fiber airframe section (both are more or less opaque >>>> to RF signals) where you need to remote mount the antenna(s). >>>> >>>> Given that you have the SMA connector on the board, the two most >>>> plausible choices are to use a short SMA male to female cable to remote >>>> the whip, or to make up a simple wire whip with an SMA on it to use as >>>> an antenna. >>>> >>>> > Peter "I just got my ham radio technical license, so *clearly* I'm an >>>> > expert on all things RF" Hackett >>>> >>>> ;-) >>>> >>>> No worries, we all started somewhere! >>>> >>>> 73 - Bdale, KB0G >>>> >>> >>> >>> _______________________________________________ >>> altusmetrum mailing list >>> [email protected] >>> http://lists.gag.com/mailman/listinfo/altusmetrum >>> >>> >> >> _______________________________________________ >> altusmetrum mailing list >> [email protected] >> http://lists.gag.com/mailman/listinfo/altusmetrum >> >> > > _______________________________________________ > altusmetrum mailing list > [email protected] > http://lists.gag.com/mailman/listinfo/altusmetrum > >
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