Spektrum SR3000 antenna length

[redshift]

....... I wanted to shorten it anyway

Had my maiden trial tonite, and a little whoopsie with the antenna.

From the Spektrum manual:

"At 8.5 inches in length, the[SR3000] antenna is significantly shorter than conventional antennas................If desired, the antenna can be shortened to exactly 3.6 inches with negligible loss of range.

I flipped 'er and cut about 1/3 off mine, so I do still have more than 3.6.

BUT.....

Is this measured from the circuit board?

They say exactly 3.6 inches, and there's two exit holes on in the case, one top, one side- and without splitting it open, I must assume these different holes are different lengths from the antenna solder point.

So here's another wonderful example of "measure with micrometers, mark with chalk, and cut with an ax" ---- they say exactly 3.6 inches, but don't bother to mention from WHERE!

I got the scissors ready, just need the word

thanks!

[GorillaMaxx360]

i am not sure where but when i cut my antenna i lot a lot of range i could not go much farther than 50 feet. i cut leaving abouut 4inches left outside of the case from side. not sure if i did it wrong of if it was falty.

[gixxer]

I believe its from the circuit board. hopefully others will be able to confirm.

[MTBikerTim]

I would say it is probably best to have at least a straight section which is 3.6 inches long. So cut a piece of antenna tube 3.6 inches long and you have your antenna. The antenna on the Losi branded spektrum receiver only has a little bit longer then 3.6 inches sticking out from the top of the case.

[redshift]

Ok it seems like I've heard about range loss (and witnessed a few) both with antenna cut or not, so another ? is, if I decide to replace the antenna wire- can I use just regular servo-lead wire, or equivalent gauge?

[lincpimp]

Nope, 2.4 antennas are like a mini coax cable. Almost impossible to repair. They may sell replacements, cause the wire just plugs in, IIRC.

[MTBikerTim]

I don't think they are linc. I think they are normal wires from memory. on the spektrum 3000 anyway.

[redshift]

Thanks for the info so far guys. I think I may have reached a verdict.

The factory length is 8.5, and I guess the measurement must be "wavelength divisible" or something to that effect, and half of that is 4.25.

4.25 minus 3.6 gives you .65", which is about the length of wire that is inside the case, I am guessing. So I think they are taking the measurement from outside.

Crossin' my fingers and going for it......

Anyone tried just cutting it off?
Think of the clean install :)

[glassdoctor]

The transmitter antenna wire has a little plug in on the end... I think the rx is a plain copper strand wire soldered to the board, like most rx's.

I have run spectrum rx's with different length wire and never had a problem. I can't imagine that a 4-5" length would be bad... I have to assume that the 3.6" spec is an minimum length, and anything longer would be ok. But the way it's mentioned in the manual makes you wonder. I think a lot of guys were measuring from the board, back when it first came out and was a new thing.

[glassdoctor]

Originally Posted by redshift

Thanks for the info so far guys. I think I may have reached a verdict.

The factory length is 8.5, and I guess the measurement must be "wavelength divisible" or something to that effect, and half of that is 4.25.

4.25 minus 3.6 gives you .65", which is about the length of wire that is inside the case, I am guessing. So I think they are taking the measurement from outside.

Crossin' my fingers and going for it......

Anyone tried just cutting it off?
Think of the clean install :)

Interesting.... it's too bad they were not more specific on this topic. Seems very obvious that they should be clear about this, but they are not.

[lincpimp]

Whoops, I have only taken the tx modues apart for my m11 and they have the coax antenna wire. I have not pulled a rx apart, but it is good to konw that it is just a std wire. Funny thing is that I rencetly pulled the fixed antenna off my cordless phone, and it has a coax antenna wire too. That was a sumbitch to solder back on...

[redshift]

Just a theory on the wavelength thing glassdoctor.

I'll try and remember to post results and range estimates- thing that sucks is I haven't had a chance to range check it at all yet, so I have no frame of reference. I've used AM/ FM forever lol.

[MTBikerTim]

The coax wire is there to shield the wire leading to the main antenna isn't it.

my Futaba FAAST radio has the coax antenna...and no matter what the instructions say I wouldnt mess with the length.....another Rx is $90....:-(

[bdebde]

I just do 3.6 antenna tube length.