BlahBlah

Hi,
I've just purchased a CB of eBay, it's a Fidelity 3000 Homebase, and it
appears to work.
I've put up a Thunderpole and got the SWR to under 2, will try to get better
when I get home in the light.

Anyhooo, although I am in a bit of a valley, I am amazed that I have not
been able to receive anyone. There have been some very weak signals but
nothing compared to what I remember. Has CB dried up or is my rig knackered
or am I too low down?

Does anyone know anything about this rig, how I could tweak it etc,
preferably step by step.

Regards
Andrew.

Road_Hog

"BlahBlah" <blah@blah.com> wrote in message
news:BE2D712E.16CEA%blah@blah.com...

Has CB dried up or is my rig knackered
> or am I too low down?


Yes, to number one, possibly to number two and probably to number three.

Where are you based?

BlahBlah

On 7/2/05 10:35 pm, in article 36q8q5F539oc7U1@individual.net, "Road_Hog"
<NoSpam@NoSpam.com> wrote:

>
> "BlahBlah" <blah@blah.com> wrote in message
> news:BE2D712E.16CEA%blah@blah.com...
>
> Has CB dried up or is my rig knackered
>> or am I too low down?
>
>
> Yes, to number one, possibly to number two and probably to number three.
>
> Where are you based?
>
>
Hi,
I'm based just outside Bridgend in South Wales. I have actually managed to
pick someone up within the last half hour or so, but he was in a truck and
no more than a mile away!

Do you know anything about these rigs and can I up the output a little to
get over them there hills?

Thx

mikeFNB

"BlahBlah" <blah@blah.com> wrote in message
news:BE2D712E.16CEA%blah@blah.com...
> Hi,
> I've just purchased a CB of eBay, it's a Fidelity 3000 Homebase, and it
> appears to work.
> I've put up a Thunderpole and got the SWR to under 2, will try to get
better
> when I get home in the light.
>
> Anyhooo, although I am in a bit of a valley, I am amazed that I have not
> been able to receive anyone. There have been some very weak signals but
> nothing compared to what I remember. Has CB dried up or is my rig
knackered
> or am I too low down?
>
> Does anyone know anything about this rig, how I could tweak it etc,
> preferably step by step.
>
> Regards
> Andrew.
>

mikeFNB

yep it's very dead.
anyway.
the fed 3000 strips are:
RX L1/2/3 . T1/2/3/45/6
TX L8/9/10/15


"BlahBlah" <blah@blah.com> wrote in message
news:BE2D712E.16CEA%blah@blah.com...
> Hi,
> I've just purchased a CB of eBay, it's a Fidelity 3000 Homebase, and it
> appears to work.
> I've put up a Thunderpole and got the SWR to under 2, will try to get
better
> when I get home in the light.
>
> Anyhooo, although I am in a bit of a valley, I am amazed that I have not
> been able to receive anyone. There have been some very weak signals but
> nothing compared to what I remember. Has CB dried up or is my rig
knackered
> or am I too low down?
>
> Does anyone know anything about this rig, how I could tweak it etc,
> preferably step by step.
>
> Regards
> Andrew.
>

deBaser

BlahBlah wrote:
> On 7/2/05 10:35 pm, in article 36q8q5F539oc7U1@individual.net,
> "Road_Hog" <NoSpam@NoSpam.com> wrote:
>
>>
>> "BlahBlah" <blah@blah.com> wrote in message
>> news:BE2D712E.16CEA%blah@blah.com...
>>
>> Has CB dried up or is my rig knackered
>>> or am I too low down?
>>
>>
>> Yes, to number one, possibly to number two and probably to number
>> three.
>>
>> Where are you based?
>>
>>
> Hi,
> I'm based just outside Bridgend in South Wales. I have actually
> managed to pick someone up within the last half hour or so, but he
> was in a truck and no more than a mile away!
>
> Do you know anything about these rigs and can I up the output a
> little to get over them there hills?
>
> Thx

Waste of time trying to tweak the output. Get a better antenna and get it
higher and then think about an amp if your still not happy

deBaser

deBaser

mikeFNB wrote:
> yep it's very dead.
> anyway.
> the fed 3000 strips are:
> RX L1/2/3 . T1/2/3/45/6
> TX L8/9/10/15
>
>
Hello Mike. Jumbo still going strong

Andy

mikeFNB

good on ya.

time for bed

bi

mike

"deBaser" <Not_Telling@someisp.com> wrote in message
news:1107823047.43813.0@dyke.uk.clara.net...
> mikeFNB wrote:
> > yep it's very dead.
> > anyway.
> > the fed 3000 strips are:
> > RX L1/2/3 . T1/2/3/45/6
> > TX L8/9/10/15
> >
> >
> Hello Mike. Jumbo still going strong
>
> Andy
>
>

tonester

BlahBlah wrote:
> Hi,
> I've just purchased a CB of eBay, it's a Fidelity 3000 Homebase, and it
> appears to work.
> I've put up a Thunderpole and got the SWR to under 2, will try to get better
> when I get home in the light.
>
> Anyhooo, although I am in a bit of a valley, I am amazed that I have not
> been able to receive anyone. There have been some very weak signals but
> nothing compared to what I remember. Has CB dried up or is my rig knackered
> or am I too low down?
>
> Does anyone know anything about this rig, how I could tweak it etc,
> preferably step by step.
>
> Regards
> Andrew.
>
I hear plenty of Welsh stations on Sunday afternoon from over here in
England. Listen at the week-end you may hear more and get to know what
channels are popular... it is less used but you should pick up quite a
few stations to talk to
Good Luck.
Tony.

P.s. i can give you a call this comming Sunday let me know if you will
be about and on what channel..call etc etc.

Tony

BlahBlah

On 7/2/05 11:44 pm, in article 73TNd.1888$XV1.768@newsfe3-win.ntli.net,
"mikeFNB" <moc.dlrowltn@FNB7G-ekim> wrote:

> yep it's very dead.
> anyway.
> the fed 3000 strips are:
> RX L1/2/3 . T1/2/3/45/6
> TX L8/9/10/15
>

Ok, I'm a numpty - what does this mean?

Remember - step by step...

Thx

mikeFNB

tuning order.
if you don't understand it.
don't do it
take it to someone

mike

"BlahBlah" <blah@blah.com> wrote in message
news:BE2ED6EB.171F6%blah@blah.com...
> On 7/2/05 11:44 pm, in article 73TNd.1888$XV1.768@newsfe3-win.ntli.net,
> "mikeFNB" <moc.dlrowltn@FNB7G-ekim> wrote:
>
> > yep it's very dead.
> > anyway.
> > the fed 3000 strips are:
> > RX L1/2/3 . T1/2/3/45/6
> > TX L8/9/10/15
> >
>
> Ok, I'm a numpty - what does this mean?
>
> Remember - step by step...
>
> Thx
>
>

BlahBlah

Hi again...
I have just had the rig back from my local CB/Ham shop, they tuned it for a
couple of quid and he said its up from 2ish to 5w and he won't take it
beyond that.

OK, mikeFNB I understand that if I don't know etc, etc but people have to
learn somewhere...
Is it possible for me to up the 'w' a little more....myself...step by step.

Andy
Aka MACMAN


On 8/2/05 11:15 pm, in article WJbOd.875$1Y.438@newsfe4-gui.ntli.net,
"mikeFNB" <moc.dlrowltn@FNB7G-ekim> wrote:

> tuning order.
> if you don't understand it.
> don't do it
> take it to someone
>
> mike
>
> "BlahBlah" <blah@blah.com> wrote in message
> news:BE2ED6EB.171F6%blah@blah.com...
>> On 7/2/05 11:44 pm, in article 73TNd.1888$XV1.768@newsfe3-win.ntli.net,
>> "mikeFNB" <moc.dlrowltn@FNB7G-ekim> wrote:
>>
>>> yep it's very dead.
>>> anyway.
>>> the fed 3000 strips are:
>>> RX L1/2/3 . T1/2/3/45/6
>>> TX L8/9/10/15
>>>
>>
>> Ok, I'm a numpty - what does this mean?
>>
>> Remember - step by step...
>>
>> Thx
>>
>>
>
>

mikeFNB

i think what you really need to understand here is a little about RF watts
out and the effect it has / does not have on how far you get out.

most bulk standard UK CB radios are designed to run at 4w, the outputs might
be capable of running 6W or on the rare occasion, depending upon the o/p
transistor fitted, 8W.

now, even if you double your o/p power, you will only put at best put an
extra 1 or 2 'S' points on the receiving stations meter.
it's not really worth it. i've always found about 20W (achieved by the use
of a burner or WHY) is the happy medium when you take into consideration
anything higher will not noticeably improve you to a far away station, but
will, noticeably improve you to nearby TV's!
if you can't get through on 20W, then it's time to look at your aerial! by
far a better solution is to improve that

there is no getting away from the old rules:

the bigger, the higher, the better!

as for how well your radio receives (RX).
it's no good putting out a good signal if your radio is deaf!
by following the makers tuning procedure, or something like i listed before
(which also gives the tuning order), you should be able to improve your
'ears' or atleast confirm it is tweaked properly. however never use a
screwdriver, use a plastic trimmer or a copper bladed one else the pot cores
will break (give me a pound!)


personally, if it's 5w i'd leave well alone! you will not get much more, it
will improve nothing other than your neighbours TVI.


mike

"BlahBlah" <blah@blah.com> wrote in message
news:BE2F066C.17360%blah@blah.com...
> Hi again...
> I have just had the rig back from my local CB/Ham shop, they tuned it for
a
> couple of quid and he said its up from 2ish to 5w and he won't take it
> beyond that.
>
> OK, mikeFNB I understand that if I don't know etc, etc but people have to
> learn somewhere...
> Is it possible for me to up the 'w' a little more....myself...step by
step.
>
> Andy
> Aka MACMAN
>
>
> On 8/2/05 11:15 pm, in article WJbOd.875$1Y.438@newsfe4-gui.ntli.net,
> "mikeFNB" <moc.dlrowltn@FNB7G-ekim> wrote:
>
> > tuning order.
> > if you don't understand it.
> > don't do it
> > take it to someone
> >
> > mike
> >
> > "BlahBlah" <blah@blah.com> wrote in message
> > news:BE2ED6EB.171F6%blah@blah.com...
> >> On 7/2/05 11:44 pm, in article 73TNd.1888$XV1.768@newsfe3-win.ntli.net,
> >> "mikeFNB" <moc.dlrowltn@FNB7G-ekim> wrote:
> >>
> >>> yep it's very dead.
> >>> anyway.
> >>> the fed 3000 strips are:
> >>> RX L1/2/3 . T1/2/3/45/6
> >>> TX L8/9/10/15
> >>>
> >>
> >> Ok, I'm a numpty - what does this mean?
> >>
> >> Remember - step by step...
> >>
> >> Thx
> >>
> >>
> >
> >
>

deBaser

mikeFNB wrote:
> i think what you really need to understand here is a little about RF
> watts out and the effect it has / does not have on how far you get
> out.
>
> most bulk standard UK CB radios are designed to run at 4w, the
> outputs might be capable of running 6W or on the rare occasion,
> depending upon the o/p transistor fitted, 8W.
>
> now, even if you double your o/p power, you will only put at best put
> an extra 1 or 2 'S' points on the receiving stations meter.
> it's not really worth it. i've always found about 20W (achieved by
> the use of a burner or WHY) is the happy medium when you take into
> consideration anything higher will not noticeably improve you to a
> far away station, but will, noticeably improve you to nearby TV's!
> if you can't get through on 20W, then it's time to look at your
> aerial! by far a better solution is to improve that
>
> there is no getting away from the old rules:
>
> the bigger, the higher, the better!
>
> as for how well your radio receives (RX).
> it's no good putting out a good signal if your radio is deaf!
> by following the makers tuning procedure, or something like i listed
> before (which also gives the tuning order), you should be able to
> improve your 'ears' or atleast confirm it is tweaked properly.
> however never use a screwdriver, use a plastic trimmer or a copper
> bladed one else the pot cores will break (give me a pound!)
>
>
> personally, if it's 5w i'd leave well alone! you will not get much
> more, it will improve nothing other than your neighbours TVI.
>
>
> mike
>
> "BlahBlah" <blah@blah.com> wrote in message
> news:BE2F066C.17360%blah@blah.com...
>> Hi again...
>> I have just had the rig back from my local CB/Ham shop, they tuned
>> it for a couple of quid and he said its up from 2ish to 5w and he
>> won't take it beyond that.
>>
>> OK, mikeFNB I understand that if I don't know etc, etc but people
>> have to learn somewhere...
>> Is it possible for me to up the 'w' a little more....myself...step
>> by step.
>>
>> Andy
>> Aka MACMAN
>>
>>
>> On 8/2/05 11:15 pm, in article WJbOd.875$1Y.438@newsfe4-gui.ntli.net,
>> "mikeFNB" <moc.dlrowltn@FNB7G-ekim> wrote:
>>
>>> tuning order.
>>> if you don't understand it.
>>> don't do it
>>> take it to someone
>>>
>>> mike
>>>
>>> "BlahBlah" <blah@blah.com> wrote in message
>>> news:BE2ED6EB.171F6%blah@blah.com...
>>>> On 7/2/05 11:44 pm, in article
>>>> 73TNd.1888$XV1.768@newsfe3-win.ntli.net, "mikeFNB"
>>>> <moc.dlrowltn@FNB7G-ekim> wrote:
>>>>
>>>>> yep it's very dead.
>>>>> anyway.
>>>>> the fed 3000 strips are:
>>>>> RX L1/2/3 . T1/2/3/45/6
>>>>> TX L8/9/10/15
>>>>>
>>>>
>>>> Ok, I'm a numpty - what does this mean?
>>>>
>>>> Remember - step by step...
>>>>
>>>> Thx


Its ironic how there is more technical chat in this ng than in
uk.radio.amateur

Keep up the good work lads

deBaser

BlahBlah

MikeFNB,
What an utterly brilliant answer.
Thanks for making sense.

I must admit that since the local CB shop tuned the rig things are looking
up. Sadly, due to my location and the amount of overhead power cables I
can't improve much on my antenna, which at the mo is an 18ft Silver Rod
mounted about 22ft up and with an SWR of 1.5 dead.

So, far nobody has complained about any TVI, and my only question is -
Do CB's affect Satellite TV too, and if so if I go for a 25w Burner, which I
believe to be the lowest I can get, will this cause more TVI?

Thanks again

Andrew aka MACMAN.

Road_Hog

"BlahBlah" <blah@blah.com> wrote in message
news:BE2FF3A7.1759B%blah@blah.com...
> MikeFNB,
> What an utterly brilliant answer.
> Thanks for making sense.
>
> I must admit that since the local CB shop tuned the rig things are looking
> up. Sadly, due to my location and the amount of overhead power cables I
> can't improve much on my antenna, which at the mo is an 18ft Silver Rod
> mounted about 22ft up and with an SWR of 1.5 dead.
>
> So, far nobody has complained about any TVI, and my only question is -
> Do CB's affect Satellite TV too, and if so if I go for a 25w Burner, which
> I
> believe to be the lowest I can get, will this cause more TVI?
>
> Thanks again
>
> Andrew aka MACMAN.


The more power you use the more likely you will cause TVI is the simplest
answer. However, where your aerial is located has some bearing on TVI as
well. Having said that 25watts isn't very much and if your aren't causing
problems with your current setup then you are unlikely to with that amount
of extra power.

Keep an eye on the SWR, the more power you put out, the more important it
becomes. As a 25watt linear will only cost £20 or less, it's owrth a try.

Liam

If you want more power you could try a Magnum DeltaForce.it has 30w built in

"BlahBlah" <blah@blah.com> wrote in message
news:BE2FF3A7.1759B%blah@blah.com...
> MikeFNB,
> What an utterly brilliant answer.
> Thanks for making sense.
>
> I must admit that since the local CB shop tuned the rig things are looking
> up. Sadly, due to my location and the amount of overhead power cables I
> can't improve much on my antenna, which at the mo is an 18ft Silver Rod
> mounted about 22ft up and with an SWR of 1.5 dead.
>
> So, far nobody has complained about any TVI, and my only question is -
> Do CB's affect Satellite TV too, and if so if I go for a 25w Burner, which
I
> believe to be the lowest I can get, will this cause more TVI?
>
> Thanks again
>
> Andrew aka MACMAN.
>

Paul Cummins

In article <mPdOd.2819$nX.1934@newsfe2-win.ntli.net>,
moc.dlrowltn@FNB7G-ekim (mikeFNB) wrote:

> now, even if you double your o/p power, you will only put at best put an
> extra 1 or 2 'S' points on the receiving stations meter.

Double output power is 3dBi.

1 s-point on a properly calibrated radio is 6dBi.

So going from 4 wats t 8 watts gives you 1/2 an 'S' point.

That might be the difference between being in the noise and being
receivable, but unless you're DXing, it will make no significant
difference to your ability to be heard.

By comparison, my 10 metre Lincoln drives a 250w amplifier with 6
settings. Each one is around a doubling of power. Between level 1 and
level 6 I add mayeb 3 s-points on mid-distance contacts (150 miles or so)
on SSB.

--
Paul Cummins - Always a NetHead
Wasting Bandwidth since 1981

Harvey

"Paul Cummins" <agree2pay4uce@spam.vlaad.co.uk> wrote in message
news:memo.20050209233838.540B@admin.vlaad.co.uk...
> In article <mPdOd.2819$nX.1934@newsfe2-win.ntli.net>,
> moc.dlrowltn@FNB7G-ekim (mikeFNB) wrote:
>
>> now, even if you double your o/p power, you will only put at best put an
>> extra 1 or 2 'S' points on the receiving stations meter.
>
> Double output power is 3dBi.
>
> 1 s-point on a properly calibrated radio is 6dBi.
>
You think CB radios have properly calibrated signal meters?????

Martin Ace

I like the technical talk. Keep it coming, because I like learning.
Martin


> Its ironic how there is more technical chat in this ng than in
> uk.radio.amateur
>
> Keep up the good work lads
>
> deBaser
>

ZZZPK

agree2pay4uce@spam.vlaad.co.uk (Paul Cummins) wrote:

: In article <mPdOd.2819$nX.1934@newsfe2-win.ntli.net>,
: moc.dlrowltn@FNB7G-ekim (mikeFNB) wrote:
:
: > now, even if you double your o/p power, you will only put at best put an
: > extra 1 or 2 'S' points on the receiving stations meter.
:
: Double output power is 3dBi.

you dont need the "i"

ZZZPK

"Harvey" <harvey@not.ntlworld.com> wrote:

: >
: You think CB radios have properly calibrated signal meters?????

in this day+age there is no reason why not.

Dave Stanton

On Fri, 11 Feb 2005 21:51:25 +0000, ZZZPK wrote:

> "Harvey" <harvey@not.ntlworld.com> wrote:
>
>
> : You think CB radios have properly calibrated signal meters?????
>
> in this day+age there is no reason why not.

Economics is why not !!

Dave

--
For what we are about to balls up may common sense prevent us doing it
again
in the future!!

Paul Cummins

In article <420d28b0.2835575@news.iol.ie>,
zzzpk_pkearn_class_a@multi_band_cb_i...om. es.it.net (ZZZPK) wrote:

> : Double output power is 3dBi.
>
> you dont need the "i"

You'd rather I used the unqualified dB?

How would that demonstrate anything? Output power into a matched antenna
system is measured in dBi, that's what I used.

--
Paul Cummins - Always a NetHead
Wasting Bandwidth since 1981

ZZZPK

Dave Stanton <me@privacy.net> wrote:

: On Fri, 11 Feb 2005 21:51:25 +0000, ZZZPK wrote:
:
: > "Harvey" <harvey@not.ntlworld.com> wrote:
: >
: >
: > : You think CB radios have properly calibrated signal meters?????
: >
: > in this day+age there is no reason why not.
:
: Economics is why not !!
and what makes you think that every manufacturer DOES NOT have the meter
calibrated ?

ZZZPK

agree2pay4uce@spam.vlaad.co.uk (Paul Cummins) wrote:

: In article <420d28b0.2835575@news.iol.ie>,
: zzzpk_pkearn_class_a@multi_band_cb_i...om. es.it.net (ZZZPK) wrote:
:
: > : Double output power is 3dBi.
: >
: > you dont need the "i"
:
: You'd rather I used the unqualified dB?
:
: How would that demonstrate anything? Output power into a matched antenna
: system is measured in dBi, that's what I used.

please do a google on dBi and the word 'isotropic'



the term to use is dB when talking about gain (or loss)
(or you can use the gain figure e.g 2-times = 3dB 4-times = 6dB )


its a liitle thing...but it will lose you marks in an exam

Dave Stanton

> How would that demonstrate anything? Output power into a matched antenna
> system is measured in dBi, that's what I used.

dbi is a theorectical gain using a point source which cannot exist in the
real world. Better to use db which everyone in the real world uses.

Dave

--
For what we are about to balls up may common sense prevent us doing it
again
in the future!!

ZZZPK

Dave Stanton <me@privacy.net> wrote:

:
: > How would that demonstrate anything? Output power into a matched antenna
: > system is measured in dBi, that's what I used.
:
: dbi is a theorectical gain using a point source which cannot exist in the
: real world. Better to use db which everyone in the real world uses.

i tried to tell him...

Dave Stanton

On Mon, 14 Feb 2005 07:05:06 +0000, ZZZPK wrote:

> Dave Stanton <me@privacy.net> wrote:
>
>
> : > How would that demonstrate anything? Output power into a matched
> : > antenna system is measured in dBi, that's what I used.
> :
> : dbi is a theorectical gain using a point source which cannot exist in
> : the real world. Better to use db which everyone in the real world uses.
>
> i tried to tell him...

Yes I know

Dave

--
For what we are about to balls up may common sense prevent us doing it
again
in the future!!

Dave Stanton

> : Economics is why not !!
> and what makes you think that every manufacturer DOES NOT have the meter
> calibrated ?

See above.....

Dave

--
For what we are about to balls up may common sense prevent us doing it
again
in the future!!

Peter

"Paul Cummins" <agree2pay4uce@spam.vlaad.co.uk> wrote in message
news:memo.20050212215524.2900A@admin.vlaad.co.uk.. .
> In article <420d28b0.2835575@news.iol.ie>,
> zzzpk_pkearn_class_a@multi_band_cb_i...om. es.it.net (ZZZPK) wrote:
>
> > : Double output power is 3dBi.
> >
> > you dont need the "i"
>
> You'd rather I used the unqualified dB?

dBi only relates to radiated power compared to an Isotropic Radiator (a theoretical
antenna which does not exist).

You are talking of signal on a meter, so the 3dB is 3dB more than a reading of
1 s-point less - it is regardless of what antenna anyone is using.
It is general, it can apply to any reading.
6 "S points" is double the signal giving 5 "S points"
8 "S points" is double the signal giving 7 "S points"
As it is not referred to a specific level or antenna, dB is correct.


Now, the confusion of 6dB, 3dB and which is double.
For current or voltage, 6dB is double.
For power, 3dB is double.

Received signal is in volts, not Watts, so 6dB is double the received signal.

> Output power into a matched antenna
> system is measured in dBi, that's what I used.

As stated, dBi only relates to signal compared to an Isotropic Radiator.
Power delivered to an antenna is measured in Watts.
An increase in power delivered to the antenna can be measured in dB.
(If you increase your CB power from 4 Watts to 8 Watts, the
increase is 3dB.)
Antenna gain can be measured in dBi or dBd.
If an antenna radiates twice as much signal (in the favoured direction)
than an Isotropic radiator does, then it has a gain of 3 dBi.
However, if it radiates twice as much signal (in the favoured direction)
than a dipole does, then it has a gain of 3 dBd.

An antenna cannot radiate more power than you put out, so that gain is
in a preferred direction - at the expence of loss in other directions


Regards,

Peter
http://www.citizensband.radiouk.com/

Paul Cummins

In article <420f36b2.137513809@news.iol.ie>,
zzzpk_pkearn_class_a@multi_band_cb_i...om. es.it.net (ZZZPK) wrote:

> please do a google on dBi and the word 'isotropic'

I' fully aware of the maning of the term Isotropic when referring to an
antenna system..

dB on it's own is entirely unqualified and meaningless.

3dB gain in reference to what, pray?


--
Paul Cummins - Always a NetHead
Wasting Bandwidth since 1981

ZZZPK

agree2pay4uce@spam.vlaad.co.uk (Paul Cummins) wrote:

: In article <420f36b2.137513809@news.iol.ie>,
: zzzpk_pkearn_class_a@multi_band_cb_i...om. es.it.net (ZZZPK) wrote:
:
: > please do a google on dBi and the word 'isotropic'
:
: I' fully aware of the maning of the term Isotropic when referring to an
: antenna system..
:
: dB on it's own is entirely unqualified and meaningless.
:
: 3dB gain in reference to what, pray?


Pul....please...

3dB is a relative measurement.

the goalpost is not specified unless it is specified in the full sentence.

3dBi clearly makes reference to an aerial that only exists on paper and
in theory and is therefore useless when talking about increasing POWER
an therefore a signal strength.

if you want to use DB to talk about POWER then use dBw or dBW

the whoe point of using a relative measurement is that you arent
interested in where the goalpost is ...just whether you have moved
to or from it. (or better or worse in terms of signal strength)


a specific example would be...

if 10 watts gives your target rx an s5 signal, then in theory
to get an s6 signal, according to wide belief, you must use 40watts
or 6dB up in power not 6dBi.


dBi refers to a goalpost known as an isotropic aerial.
an aerial that only exists in theory.


dBw refers to a goalpost of 1 milliwatt of power (maybe across a specific
R or Z or something)

dBW refers to a goalpost of 1 WATT of power (again maybe across a specific
R or Z or something)

a dipole has i think 1.7 dBi gain.
i.e its better by (i think) a factor of 2.1 times in collecting or
radiating the signal to its sides (not out the ends of it) than THE SAME
ISOTROPIC or IN-THEORY AERIAL.



dB is a relative scale to another point.
the actual point can be almost anything.




ask your boss for a 3dB pay-rise next time <<smile>>
which is equivalent to a 200% increase...

increase relative to what ???

YOUR CURRENT PAYPACKET... ** ANOTHER GOALPOST **


now i may not have a degree in electonics but
i think i'd get 8/10 for the above.

Paul Cummins

In article <4212632a.3419792@news.iol.ie>,
zzzpk_pkearn_class_a@multi_band_cb_i...om. es.it.net (ZZZPK) wrote:

> 3dB is a relative measurement.

exactly.

3dB increase in receive strength is meaningless.

1 's' point is 6dBv difference in received field strength.

--
Paul Cummins - Always a NetHead
Wasting Bandwidth since 1981

ZZZPK

agree2pay4uce@spam.vlaad.co.uk (Paul Cummins) wrote:

: In article <4212632a.3419792@news.iol.ie>,
: zzzpk_pkearn_class_a@multi_band_cb_i...om. es.it.net (ZZZPK) wrote:
:
: > 3dB is a relative measurement.
:
: exactly.
:
: 3dB increase in receive strength is meaningless.

no its not...

its better than a 3dB drop in signal strength

ZZZPK

agree2pay4uce@spam.vlaad.co.uk (Paul Cummins) wrote:


: 1 's' point is 6dBv difference in received field strength.


and YOU have just used dBv



if youre an expert explain the term 6dBv

especially the 6dB part.