Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
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. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
One more opinion of mine | Policy | |||
Please send me your opinion about my project as placed on | Equipment | |||
Please send me your opinion about my project as placed on | Digital | |||
Please send me your opinion about my project as placed on | Digital | |||
What's your opinion on Radio Listener's Database software | Shortwave |