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Old September 1st 05, 12:40 AM
Roy Lewallen
 
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Here's another posting referring to 6 dB "S-units". Have you actually
measured how many dB between marks on your receiver's S meter? I have.
Here's what they are, on my Icom IC-730, 40 meters, preamp off:

S1-S2: 1.4 dB
S2-S3: 1.3 dB
S3-S4: 1.6 dB
S4-S5: 2.3 dB
S5-S6: 1.8 dB
S6-S7: 3.2 dB
S7-S8: 3.1 dB
S8-S9: 4.0 dB
S9 - S9+10 dB: 5.6 dB
S9+10 - S9+20: 7.3 dB
S9+20 - S9+30: 6.6 dB
S9+30 - S9+40: 10.5 dB
S9+40 - S9+50: 11.3 dB
S9+50 - S9+60: 13.5 dB

So if I put up an antenna with 7 dB gain over a dipole (about par for a
3 element Yagi), it would kick my S meter from S2 to S6 when switching
from the dipole to the Yagi. If I assumed my "S units" were 6 dB, I'd
conclude my antenna had 24 dB gain. I'd be mistaken by a factor of 50 --
that is, I'd think my antenna had the gain of an array of about 50 Yagis.

I don't understand why we need a 6 dB unit which doesn't bear any fixed
relationship to the marks on an S meter. Why not just use dB? Most hams
can't measure 6 dB "S units" any better than they can measure dB.

I've got it. When somebody asks for a signal comparison and it's a 7 dB
difference, I'll just tell him "My S meter went from S2 to S6, which is
a difference of 1.2 S units." Everyone should understand that, right?

Roy Lewallen, W7EL

Ham op wrote:
7.78 Db BETTER [+1 1/4 S unit] than 100 watts.

Upgrade the vertical to a beam and the net gain can be as high as +19.78
dB [3+ S units] on the path:
1] + 6 dB in receive
2] + 6 dB in transmit
3] + 7.78 dB for the amplifier.

For $1400, a beam has a much better return on investment than an
amplifier by itself.

The #1 rule I teach new or aspiring hams is "Your station efficiency,
and your enjoyment, is directly proportional to your antenna."



Dave wrote:

How does the ALS600 do when using with the Butternut HF9V vertical?


"Ham op" wrote in message
...

Dave wrote:

I am thinking of buying the Ameritron 600 watt solid state amp and was
wondering what opinions you all may have of it. Thanks



How many $per watt for the Ameritron 600? Ameritron lists the ALS-600 at
$1299. For base station usage you need the power supply. Total package
list price of $1428. Or, $2.38 per watt [SSB]. [600 watt]

The AL-811H lists for $799 or $1.00 per watt [SSB]. [800 watt]

The AL-80B lists for $1349 or $1.39 per watt [SSB]. [1000 watt]

The AL-1500 lists for $3045 or $2.03 per watt [SSB]. [1500 watt]

If you are considering base usage the AL-811H is less than 1/2 S unit
below the AL-1500 at about 1/2 the price.

The ALS-600 is only 1 1/4 S units above a 100 watt base or mobile
station.

I own the AL-80B. It has about 1/4 S unit below the AL-1500. [SSB]

Save some money and put it to good use on your antenna system.






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