Radio Safety

[TyBreaker]

I was told that when using a CB radio, you should not operate the radio
with the antenna disconnected because it puts a strain on the
transmitter and can cause damage.

Is it similar with RC transmitters? Eg. is it bad to operate the
transmitter with the antenna connected but fully or semi-retracted?
--
______ ___ __
/_ __/_ __/ _ )_______ ___ _/ /_____ ____
/ / / // / _ / __/ -_) _ `/ '_/ -_) __/
/_/ \_, /____/_/ \__/\_,_/_/\_\\__/_/
/___/

There are 10 types of people in this world; those who understand the
binary numbering system and those who don't.

There's no place like 127.0.0.1.

ASCII a silly question, get a silly ANSI.

[\Doc\]

"TyBreaker" <tybreakerNO@SPAMhotmail.com> wrote in message
news:4461008e@dnews.tpgi.com.au...
>I was told that when using a CB radio, you should not operate the radio
>with the antenna disconnected because it puts a strain on the transmitter
>and can cause damage.
>
> Is it similar with RC transmitters? Eg. is it bad to operate the
> transmitter with the antenna connected but fully or semi-retracted?

No.

Doc

///////////////////////////////////////////////////////////////////////////////////////
> --
> ______ ___ __
> /_ __/_ __/ _ )_______ ___ _/ /_____ ____
> / / / // / _ / __/ -_) _ `/ '_/ -_) __/
> /_/ \_, /____/_/ \__/\_,_/_/\_\\__/_/
> /___/
>
> There are 10 types of people in this world; those who understand the
> binary numbering system and those who don't.
>
> There's no place like 127.0.0.1.
>
> ASCII a silly question, get a silly ANSI.

[Honest John]

Beg to differ.
I looked through a few manuals, this sounded similar.
Manual for my Hitec Lynx states on page 4:

Warning!!! Always extend your antenna as not to overload the
circuitry when radio is on.

I remember this in an aircraft radio manual too. Don't remember the brand.
FWIW.

John



""Doc"" <nospam@noway.com> wrote in message
news:obudncfRq-FF0_zZnZ2dnUVZ_tSdnZ2d@adelphia.com...
>
> "TyBreaker" <tybreakerNO@SPAMhotmail.com> wrote in message
> news:4461008e@dnews.tpgi.com.au...
>>I was told that when using a CB radio, you should not operate the radio
>>with the antenna disconnected because it puts a strain on the transmitter
>>and can cause damage.
>>
>> Is it similar with RC transmitters? Eg. is it bad to operate the
>> transmitter with the antenna connected but fully or semi-retracted?
>
> No.
>
> Doc
>
> ///////////////////////////////////////////////////////////////////////////////////////
>> --
>> ______ ___ __
>> /_ __/_ __/ _ )_______ ___ _/ /_____ ____
>> / / / // / _ / __/ -_) _ `/ '_/ -_) __/
>> /_/ \_, /____/_/ \__/\_,_/_/\_\\__/_/
>> /___/
>>
>> There are 10 types of people in this world; those who understand the
>> binary numbering system and those who don't.
>>
>> There's no place like 127.0.0.1.
>>
>> ASCII a silly question, get a silly ANSI.
>
>

[\Doc\]

"Honest John" <theloraxDELETETHIS@wi.rr.com> wrote in message
news:Irx8g.67796$Tf1.8423@tornado.rdc-kc.rr.com...
> Beg to differ.
> I looked through a few manuals, this sounded similar.
> Manual for my Hitec Lynx states on page 4:
>
> Warning!!! Always extend your antenna as not to overload the
> circuitry when radio is on.
>
> I remember this in an aircraft radio manual too. Don't remember the brand.
> FWIW.
>
> John

Think about it. The antenna is connected to the circuit board. Regardless
if the antenna is extended or not, the same "load" is being placed on the
circuitry as the antenna mass and size is the same, retracted or extended.

Antenna unscrewed and unattached...................different story.

Doc

[Richard]

""Doc"" <nospam@noway.com> wrote in message
news:1qKdnXorW68iIf_ZnZ2dnUVZ_tCdnZ2d@adelphia.com ...
>
> "Honest John" <theloraxDELETETHIS@wi.rr.com> wrote in message
> news:Irx8g.67796$Tf1.8423@tornado.rdc-kc.rr.com...
> > Beg to differ.
> > I looked through a few manuals, this sounded similar.
> > Manual for my Hitec Lynx states on page 4:
> >
> > Warning!!! Always extend your antenna as not to overload the
> > circuitry when radio is on.
> >
> > I remember this in an aircraft radio manual too. Don't remember the
brand.
> > FWIW.
> >
> > John
>
> Think about it. The antenna is connected to the circuit board.
Regardless
> if the antenna is extended or not, the same "load" is being placed on the
> circuitry as the antenna mass and size is the same, retracted or extended.
>
> Antenna unscrewed and unattached...................different story.
>
> Doc

Sorry, but in this situation size does matter. Mass has little to do with
it. If you would like to put your theory about mass to practise take your
receiver antenna and scrunch it up into a little ball and tape it down
inside your truck some where and see what happens to your range, even better
do it with the transmitter antenna down and if your theory is correct you
should be able to get full range with the failsafe disconnected of course.
:-) I bet you it doesn't. A receiver works the same as a transmitter and
also requires a tuned antenna and needs it to be fully extended for best
performance.

Most RC transmitters new and old have a built in preload circuit of some
sort to reduce the effect of needing a tuned antenna system like they do in
CB transmitters. Thus having a preloaded circuit you don't have to worry
about overloading the circuit as much as you would with a CB transmitter if
you have no antenna connected or the antenna partially extended. There is
also the understanding that in low power devices like RC transmitters that
the circuit does not need protection from overload because the voltage is
never a constant and power output of the transmitter is not high enough to
cause effective damage to the unit. We're talking about <100 mili-watts for
a RC transmitter as apposed to a CB transmitter of 4+ watts (40X greater
power).

An example of this preload in the antenna circuit is simply put, if you
don't have this circuit your antenna would have to be approx. 11 meters long
if you were using a 27Mhz RC transmitter.

Take a CB antenna and fold it in half and bad things happen the same thing
applies to RC transmitters but not to the same extent as a CB transmitter
because of the lower power output and preloading circuit.

One thing that is relevant is if you use your RC transmitter with no antenna
or the antenna down you will consume more battery power, of course given
that a Futaba 3PM has a current drain of 250mA or less means little or
nothing to a set of 2600ma rechargeable batteries but to a set of Alkaline
that are rated at 500ma it means a lot.

Its mostly about SWR, VSWR or ISWR, here is a article relating to what your
talking about above. The last paragraph of the article relates directly to
what you guys are talking about with RC transmitters.

http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci852555,00.html

Hope this helps, one thing I no doesn't is getting the relevant information
from RC manufacturers about the power output and circuitry of the radio
equipment. I'm actually surprised the US government doesn't require this
information to be included in the manuals specially where digital and high
frequency (microwave) transmitters are becoming more common and the effect
of radiation from these transmitters could cause health problems in
children.



Cheers
Richard

[TyBreaker]

Honest John wrote:
> Beg to differ.
> I looked through a few manuals, this sounded similar.
> Manual for my Hitec Lynx states on page 4:
>
> Warning!!! Always extend your antenna as not to overload the
> circuitry when radio is on.
>
> I remember this in an aircraft radio manual too. Don't remember the brand.
> FWIW.

My CB mate spoke in similar terms for CB radios and I was wondering if
it was basic radio theory in which case it would apply to any
transmitter. I'm assuming a receiver doesn't matter because the worse
that can happen is you don't pick up a good signal with the aerial
down/disconnected but at least the circuitry doesn't get stressed by a
poor signal (might be wrong).

I guess to be safe I'll ensure my aerial is extended anyway - the
thought entered my head after I shelled out a significant amount for a
radio for my truck :)
--
______ ___ __
/_ __/_ __/ _ )_______ ___ _/ /_____ ____
/ / / // / _ / __/ -_) _ `/ '_/ -_) __/
/_/ \_, /____/_/ \__/\_,_/_/\_\\__/_/
/___/

There are 10 types of people in this world; those who understand the
binary numbering system and those who don't.

There's no place like 127.0.0.1.

ASCII a silly question, get a silly ANSI.

[DanTXD]

"Richard" <DK@hotmail.com> wrote in message
news:4462da9a$1@quokka.wn.com.au...
>
> ""Doc"" <nospam@noway.com> wrote in message
> news:1qKdnXorW68iIf_ZnZ2dnUVZ_tCdnZ2d@adelphia.com ...
>>
>> "Honest John" <theloraxDELETETHIS@wi.rr.com> wrote in message
>> news:Irx8g.67796$Tf1.8423@tornado.rdc-kc.rr.com...
>> > Beg to differ.
>> > I looked through a few manuals, this sounded similar.
>> > Manual for my Hitec Lynx states on page 4:
>> >
>> > Warning!!! Always extend your antenna as not to overload the
>> > circuitry when radio is on.
>> >
>> > I remember this in an aircraft radio manual too. Don't remember the
> brand.
>> > FWIW.
>> >
>> > John
>>
>> Think about it. The antenna is connected to the circuit board.
> Regardless
>> if the antenna is extended or not, the same "load" is being placed on the
>> circuitry as the antenna mass and size is the same, retracted or
>> extended.
>>
>> Antenna unscrewed and unattached...................different story.
>>
>> Doc
>

<snip theory>

Not debating the theory, it may well be right, but I do it all the time and
I've never fried a tranny :-)

--
Dan

[Backbone]

"TyBreaker" <tybreakerNO@SPAMhotmail.com> wrote in message
news:4461008e@dnews.tpgi.com.au...
> I was told that when using a CB radio, you should not operate the radio
> with the antenna disconnected because it puts a strain on the
> transmitter and can cause damage.
>
> Is it similar with RC transmitters? Eg. is it bad to operate the
> transmitter with the antenna connected but fully or semi-retracted?

Yup - your batteries life will be shortened as well as frequency bleed
over - you could effect some else's radio or perhaps your own radio will be
effected

[DanTXD]

"Backbone" <backboneaccessflaps@flapsverizon.net> wrote in message
news:WcOdnegLU4BEF_rZRVn-rg@giganews.com...
> ""Doc"" <nospam@noway.com> wrote in message
> news:1qKdnXorW68iIf_ZnZ2dnUVZ_tCdnZ2d@adelphia.com ...
>>
>> "Honest John" <theloraxDELETETHIS@wi.rr.com> wrote in message
>> news:Irx8g.67796$Tf1.8423@tornado.rdc-kc.rr.com...
>> > Beg to differ.
>> > I looked through a few manuals, this sounded similar.
>> > Manual for my Hitec Lynx states on page 4:
>> >
>> > Warning!!! Always extend your antenna as not to overload the
>> > circuitry when radio is on.
>> >
>> > I remember this in an aircraft radio manual too. Don't remember the
> brand.
>> > FWIW.
>> >
>> > John
>>
>> Think about it. The antenna is connected to the circuit board.
> Regardless
>> if the antenna is extended or not, the same "load" is being placed on the
>
> NO - that's wrong! More power would be required if the antenna were
> shortened!!
>
>> circuitry as the antenna mass and size is the same, retracted or
>> extended.
>>
>> Antenna unscrewed and unattached...................different story.
>
> What changes the frequency in your FM or AM radio - think about it - a
> length of wire is lengthened! will it change the frequency. If I were to
> change the length of the antenna wire, would the frequency change or bleed
> over into another freq. - How about the receiver ie does this work for
> the
> receiver as well eg if I cut an inch off my receiver wire!!!
>

Hold on. Are you saying that opening/closing the antenna changes the
frequency, or were you taking the piss?

--
Dan

[\Doc\]

"Backbone" <backboneaccessflaps@flapsverizon.net> wrote in message
news:ZsednUryP6EbbvrZnZ2dnUVZ_sOdnZ2d@giganews.com ...
> LOL yer not very bright are you?!! Hahahaha, fits a pedophile scumbag
> profile!! Look Mr DK you obviously don't have a clue as to what yer
> talkin
> about... Perhaps you should refrain from acting like a know it all.
> Giving
> bad advice is simply not cool!

First, I'm curious as to where the pedophile remarks are coming
from..................anyways, a piece of advice...........seeing as how I'm
not a pedophile................ being called such doesn't bother me, so you
might want to dig thru the arsenal for a different insult that <might>
actually bother me, although that is unlikely as well.

Second, I might not know everything about radio electronics, but I do know
that changing the length of rx wire or tx antenna length does not change the
frequency.

You've been very, very wrong on just about everything you've ever posted
about on here. I do believe people will be more inclined to listen to me
than you based on our respective track records.

Doc

[\Doc\]

"DanTXD" <me@privacy.net> wrote in message
news:4cq9auF16ihb9U1@individual.net...
>> What changes the frequency in your FM or AM radio - think about it - a
>> length of wire is lengthened! will it change the frequency. If I were to
>> change the length of the antenna wire, would the frequency change or
>> bleed
>> over into another freq. - How about the receiver ie does this work for
>> the
>> receiver as well eg if I cut an inch off my receiver wire!!!
>>
>
> Hold on. Are you saying that opening/closing the antenna changes the
> frequency, or were you taking the piss?
>
> --
> Dan

Uhhhhh, yeah, that's what he was saying. Remember his brilliant explanation
about how switching nitro contents will "seize" your motor?

Doc

[DanTXD]

""Doc"" <nospam@noway.com> wrote in message
news:_8mdnXCr95nfZ_rZnZ2dneKdnZydnZ2d@adelphia.com ...
>
> "DanTXD" <me@privacy.net> wrote in message
> news:4cq9auF16ihb9U1@individual.net...
>>> What changes the frequency in your FM or AM radio - think about it - a
>>> length of wire is lengthened! will it change the frequency. If I were to
>>> change the length of the antenna wire, would the frequency change or
>>> bleed
>>> over into another freq. - How about the receiver ie does this work for
>>> the
>>> receiver as well eg if I cut an inch off my receiver wire!!!
>>>
>>
>> Hold on. Are you saying that opening/closing the antenna changes the
>> frequency, or were you taking the piss?
>>
>> --
>> Dan
>
> Uhhhhh, yeah, that's what he was saying. Remember his brilliant
> explanation about how switching nitro contents will "seize" your motor?
>

I'm sure we're just mis-understanding what he's saying. Cos really, that's
just silly....

--
Dan