| Author |
Message |
    
Blackjack
Member
Username: Blackjack
Post Number: 52
Registered: 2-2007
| | Posted on Monday, September 14, 2009 - 10:19 am: | 
|
SINCE NO'ONE COULD ANSWER MY QUESTION IN REGARDS TO THE SS158 SHOWING LOW R.M.S. WATTAGE,,,,, MAYBE SOME'ONE COULD ANSWER IF 2 RADIOS ARE TESTED FOR RF OUTPUT RADIO ,WILL THE 1 THAT IS PUTTING OUT MORE HARMONICS THAN THE OTHER RADIO SHOW A GREATER RF OUTPUT ? I ASK BECAUSE I WAS TOLD THE ONLY WAY OF MEASURING HARMONICS IS ON A SPECTRUM ANALYZER,,,NOT ON ANY TYPE OF ANALOG METER,,,,BIRD METER INCLUDED.... |
Five
Junior Member
Username: Five
Post Number: 23
Registered: 7-2009
| | Posted on Monday, September 14, 2009 - 3:48 pm: |
|
That is correct! The only way to measure harmonics is with a spectrum analyzer. A dirty radio(over modulated)produces harmonics that is why a radio with harmonics can transmit into another band or frequency. Without a spectrum analyzer you cannot see the harmonics. A good tech should use one with his scope to make sure the radio is as clean as it can be. Most techs do not use one do to the cost of the spectrum analyzer. They are expensive but well worth it. Hope this helps... |
Blackjack
Member
Username: Blackjack
Post Number: 53
Registered: 2-2007
| | Posted on Monday, September 14, 2009 - 7:49 pm: |
|
Hey Five,,,thanx for the reply brother,,,when you get a chance,,,,if you didnt read the post i wrote in this column a few days ago in regards to the ranger ss158 rms output of only a few watts comapred to a tuned up uniden 78 doing 3 times the rms output,,,,,,,,,,,,,,let me know what your input is on that,,,,,,, maybe something to do with harmonics or such im guessing,,,thanx again |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4655
Registered: 7-2004
| | Posted on Monday, September 14, 2009 - 10:46 pm: |
|
actually, if you put a good rfi filter on a radio producing tons of trash.....you SHOULD see a DECREASE in power output on a wattmeter. not a lot, but some. the wattmeter just shows you WHAT the power OUTPUT is. it isn't TELLING you that all of your power isn't necessarily on the intended freq, but everywhere, and, lacking a spectrum analyzer, the locals tell you how much in the way of harmonics you are producing. angrily. |
Blackjack
Member
Username: Blackjack
Post Number: 54
Registered: 2-2007
| | Posted on Tuesday, September 15, 2009 - 10:15 am: |
|
Hey Pat,,,, im thinking this very well could be the reason that a souped up uniden 78 beat the ranger ss 158 in rms/average output on the bird meter ? totally different type of radio,harmonics being generated,,,shielding/ground in radio etc .......make sense ? |
Tech833
Moderator
Username: Tech833
Post Number: 1743
Registered: 8-2002
| | Posted on Tuesday, September 15, 2009 - 11:19 am: |
|
Spurs, harmonics, and other types of transmitter noise will all add to the reading on a wattmeter.
Harmonics CAN be determined without a spectrum analyzer, although not very accurately. If you have a general coverage receiver that can tune in the various harmonic frequencies, you can tune them in and see if they are present, or how strong they are. If you are unable to receive harmonics, chances are good that your transmitter is pretty clean.
The best way to observe (and measure) spurs and harmonics is indeed with a spectrum analyzer. |
Blackjack
Member
Username: Blackjack
Post Number: 55
Registered: 2-2007
| | Posted on Tuesday, September 15, 2009 - 12:59 pm: |
|
Thank you for the reply Tech 833,,,,, it is well appreciated..... |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4657
Registered: 7-2004
| | Posted on Tuesday, September 15, 2009 - 4:56 pm: |
|
regarding paul's answer....that's what i said mark  !!! again, lacking a spectrum analyzer, ask the locals & your neighbors-they WILL tell you how much trash you are producing....remember when the townsfolk persued frankenstein's monster-you'll get the same reaction! |
|
