under construction ..............
bilingual lower in Greek
Today two reference values exist: for frequencies
below 30 MHz,
S9 is defined as a voltage of
50 μV over 50 Ω at
the receiver antenna connector; for frequencies
above 30 MHz, S9
is defined as a voltage of
5 μV over 50 Ω at the
receiver antenna connector.
This refers to an unmodulated carrier signal that uses almost no bandwidth; in case
of real signals using a given bandwidth, this definition may not be enough
since a smaller receiver bandwidth allows a weaker minimum detectable signal,
but S-points are still a good tool for comparing received signals.
S-points for frequencies below 30 MHz:
Signal
strength |
Relative
intensity |
Received
voltage |
Received power
(Zc = 50 Ω) |
| S1 |
–48 dB |
0.20 μV |
–14 dBμV |
790 aW |
–121 dBm |
| S2 |
–42 dB |
0.40 μV |
–8 dBμV |
3.2 fW |
–115 dBm |
| S3 |
–36 dB |
0.79 μV |
–2 dBμV |
13 fW |
–109 dBm |
| S4 |
–30 dB |
1.6 μV |
4 dBμV |
50 fW |
–103 dBm |
| S5 |
–24 dB |
3.2 μV |
10 dBμV |
200 fW |
–97 dBm |
| S6 |
–18 dB |
6.3 μV |
16 dBμV |
790 fW |
–91 dBm |
| S7 |
–12 dB |
13 μV |
22 dBμV |
3.2 pW |
–85 dBm |
| S8 |
–6 dB |
25 μV |
28 dBμV |
13 pW |
–79 dBm |
| S9 |
0 dB |
50 μV |
34 dBμV |
50 pW |
–73 dBm |
| S9+10 |
10 dB |
160 μV |
44 dBμV |
500 pW |
–63 dBm |
| S9+20 |
20 dB |
500 μV |
54 dBμV |
5.0 nW |
–53 dBm |
| S9+30 |
30 dB |
1.6 mV |
64 dBμV |
50 nW |
–43 dBm |
| S9+40 |
40 dB |
5.0 mV |
74 dBμV |
500 nW |
–33 dBm |
| S9+50 |
50 dB |
16 mV |
84 dBμV |
5.0 μW |
–23 dBm |
| S9+60 |
60 dB |
50 mV |
94 dBμV |
50 μW |
–13 dBm |
S-points for frequencies above 30 MHz:
Signal
strength |
Relative
intensity |
Received
voltage |
Received power
(Zc = 50 Ω) |
| S1 |
–48 dB |
20 nV |
–34 dBμV |
7.9 aW |
–141 dBm |
| S2 |
–42 dB |
40 nV |
–28 dBμV |
32 aW |
–135 dBm |
| S3 |
–36 dB |
79 nV |
–22 dBμV |
130 aW |
–129 dBm |
| S4 |
–30 dB |
160 nV |
–16 dBμV |
500 aW |
–123 dBm |
| S5 |
–24 dB |
320 nV |
–10 dBμV |
2.0 fW |
–117 dBm |
| S6 |
–18 dB |
630 nV |
–4 dBμV |
7.9 fW |
–111 dBm |
| S7 |
–12 dB |
1.3 μV |
2 dBμV |
32 fW |
–105 dBm |
| S8 |
–6 dB |
2.5 μV |
8 dBμV |
130 fW |
–99 dBm |
| S9 |
0 dB |
5.0 μV |
14 dBμV |
500 fW |
–93 dBm |
| S9+10 |
10 dB |
16 μV |
24 dBμV |
5.0 pW |
–83 dBm |
| S9+20 |
20 dB |
50 μV |
34 dBμV |
50 pW |
–73 dBm |
| S9+30 |
30 dB |
160 μV |
44 dBμV |
500 pW |
–63 dBm |
| S9+40 |
40 dB |
500 μV |
54 dBμV |
5.0 nW |
–53 dBm |
| S9+50 |
50 dB |
1.6 mV |
64 dBμV |
50 nW |
–43 dBm |
| S9+60 |
60 dB |
5.0 mV |
74 dBμV |
500 nW |
–33 dBm |
Older receivers were calibrated using the old standard that defined S9 as a
voltage of 100 μV instead of 50 μV over 50 Ω at the receiver
antenna connector
QRP and QRO can get along
QRP and QRO can get along - meaning,
you can have both and have twice the fun. But having a really nice
antenna makes a far bigger difference than a really nice amp. Some hams
can't afford to put up a fancy antenna system so they have to get their
gain via amplification, some can't afford the amp but can afford to put up
a well-dressed antenna. The point is we get our kicks in different
ways.
QRO has a rewarding feel when you realize you need to replace your 2000
watt wattmeter, or watching a pair of 3-500Z tubes turn color. I'll be
the first to admit that I like running a 1000 watt CW signal and the full
legal limit on SSB. But it isn't necessary to exceed 1000 watts PEP - I
wish it made a difference but it doesn't. Pay close attention to the Decibel below to understand why.
The Decibel
More important than anything else that a ham should know
is what the decibel is. Too few hams understand why a 5 watt signal can reach
from Boston to Sacramento when 20 meters has almost folded for the evening.When
it comes to running lots of power - "Biger's better, crank it up and dim
the lights!" Well, that's true to a point, but knowing where that
"point" is and how to find it can sometimes be confusing. Fortunately
for us, defining where the "point" is can be defined with simple
terms. The "point" that we reach where more power makes little
difference is, for hams, around 1000 watts. Anything over 1000 watts is mostly
pouring sand down a rat hole. It took a long time for this to soak into my
brain... Why is this true? The decibel!
It is difficult for a person, especially most new hams these days, to fully
appreciate the decibel. Wattmeters make it easy to see a large change in output
power by watching the needle move its entire distance but this change doesn't
really mean much when you think about what amplification really is. For a
person to increase their output power level by 3dB, you must double your power
output. For 9dB gain you must multiply your current power output by 8. For SSB
operation you need approximately 10dB gain (precisely 1.67 S-units, 10x your
output power) to make a clearly noticeable improvement to the person listening
on the other side. So what does this mean in plain English?
For hams saying QRP is a waste of time, a 5 watt radio is only about 2 S units
below someone running around 100 watts:
- 5 watts output x 8 = 40
watts (this is 9dB gain)
- 40 x 2 = 80 watts output =
12dB total gain (only 2 S units over 5 watts output!)
2 S units below a 100 operator is typically a 559 report
vs 579 report. And if the band is going down for the day the dB attenuation
(30dB or more) far exceeds what we are able to dump into the air.
For hams who typically run 80-140 watts output:
- 10 watts output x 8 = 80
watts (this is 9dB gain)
- Typical ham running 80
watts output x 8 = 640 watts (this is another 9dB gain)
- Contester running 640 watts
output x 8 = 5120 watts (this is another 9dB gain)
To make a real difference to the receiving station, 5120
watts are needed over 640! That's a kick in the pants, eh? But what about SSB
operation and 10dB gain? More numbers:
- 10 watts output x 10 = 100
watts (this is 10dB gain)
- 100 watts output x 10 =
1000 watts (this is 10dB gain)
- 1000 watts output x 10 =
10000 watts (this is 10dB gain)
It's getting worse by the minute! A typical rig at 100
watts makes a big splash at 1000 watts... but requires 10,000 watts for the
same sized jump from 1,000? Yes! And for some reason, thousands more dollars
are spent to get a 2500 watt amplifier instead of a 1300 watt amplifier - but
why??
QRO Power!
Okay, well, there is some creedence to a 2500 watt
amplifier. It's bigger than your friends' amps, you can have your own lightshow
on demand by simply keying it and watching your neighborhood's lights dim, you
can prove to yourself that it's really getting you around the world because
your electricity bill is $200 a month more than it used to be... and it's
heavier. Oh yes, there's also another 3dB going out the line but whether or not
you have melted or burned things in-line or caused your neighbors' ground-fault
interruption system to trip from induced current is another matter. There are
those among us who will claim that the additional 3dB makes the difference
between a successful or unsuccessful contact - possibly for CW but highly
doubtful for any other mode. The only thing you get out of a "Really
Big"(tm) amplifier is bringing up the signal strength (aka,
"loudness") of your conversation when you are not yelling into the
microphone at 100% modulation. Most conscientious hams will use a little
processing to compress their speech and improve intelligibility. So at an
average conversation level of 60 watts PEP and using the formula above we get
the figures below:
- 60 x 10 = 600 watts (10dB,
2 S Units)
- 600 x 10 = 6000 watts
Ouch. 6,000
watts to go from S6 to S9? Yes. But from 60 to 600 you're almost at S8. Getting
from S8 to S9 is one tough climb. The best benefit that is very nice about
these giant amps is you don't have to push your exciter so hard. A relaxed
exciter produces cleaner output with minimal distortion products. That is
really what we want - cleaner signal on the band and less strain and wear on
your equipment.
I did not mention above, but no radio will show a linear S-unit gain for each
5dB of signal. Search hard enough and you will find that various brands of
radios will need only 2dB for the first 3 S-units, 5dB for the next 4 and so on
- others have a completely diferent pattern. You have to use your own judgement
and base RST how much stronger the remote station is above the noise floor.
If you want to know if your amp is splattering, use what I call the "Wave
Meter" - wave at your neighbors; if they wave back you're okay
ΑΚΟΥΩ ΣΕ ΕΛΛΗΝΙΚΑ ΠΗΓΑΔΑΚΙΑ ΠΟΛΛΟΥΣ ΕΛΛΗΝΕΣ ΡΑΔ/ΝΕΣ ΝΑ ΧΡΗΣΙΜΟΠΟΙΟΥΝ ΤΕΡΑΣΤΙΕΣ ΙΣΧΕΙΣ (> 500 ) ΓΙΑ ΕΠΑΦΕΣ ΕΝΤΟΣ ΕΛΛΑΔΟΣ !!!
Το πρώτο ερωτημα που μου ερχεται στο μυαλο ειναι : 1. Γιατι οι εταιρίες φτιαχνουν πολυ ακριβα μηχανηματα που εκπεμπουν με 100 watt μονο?
Πολλα μηχανηματα με ισχή 100 watt κοστιζουν 10.000 Ευρώ
Βεβαιως μια απο τις απαντησεις ειναι η εξής: Για να σου πουλήσουν και εναν ακριβο ενισχυτη.
Αλλη μια μοδα ειναι το εγω το εχω ποιο μεγαλο ?
Απο τοτε που βγηκαν οι λάσπες τα αγορακια εχουν αυτο το κομπλεξ.
Το : Ποιος ειναι ο καλύτερος ειναι κατι που τυραναει τους ανδρες απο το DNA τους.
Και βεβαια ειναι στο DNA των ανδρών αυτο, γιατι υπερισχύει ο νόμος του Δαρβίνου .
Το καλυτερο DNA θα επιβιώσει.
Ετσι λοιπον ξεκιναει μια ιστορια 10.000 ετων που δεν ειναι Ραδιοερασιτεχνική αλλά Ανδρική θα μπορουσα να πω hi.
Κι ομως κι εγω θα παω διακοπες το καλοκαιρι με autostop κι εσυ με την Rolls . και ειναι το ιδιο πιθανον να περασω καλυτερα με το κοριτσι μου απο ότι εσυ με την γρια σου στην Rolls hi .
Ομως καλο θα ηταν να σταματησω το προκλητικο γραψιμο και να μπω στην ουσία του θέματος μου.
| under construction |
YAESU FL 2100B
some read about 1200 input and think they will have 1KW out..
No
550w out is good for this
linear on 1200 input. Max and ideal would be 600w and don't expect more.
But take care, do not exceed 100w input peaks ! Οtherwise will damage
some components and eventually the valves . Don't forget you have 2400
volts there ! it's the top for 572Bs !! good dx and before all these,
take serius care on your antenna efficiency.
