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need input weather 1/2 or 5/8 wave
- Thread starter 1iwilly
- Start date
5/8th wave all day long over a 1/2 wave.I'll take the extra gain for both transmit & receive any day.
SIX-SHOOTER
W4KVW
SIX-SHOOTER
W4KVW
i went with the Sirio 2016 be here sometime this week
My Sirio 2016 has been up a year now. Survived two thunder storms this past week of 60+ mph wind speed. Still shines like a new one.
That extra one dB of gain won't amount to a hill of beans really. Having said that I would take the 5/8 wave simply because the lobe is split and favours both high angle and low angle propagation. A half wave may tend to be a tad better on really low angle signals but is beat out at the higher angle by the 5/8.
Every db counts since most people don't factor in the losses from each connector & it only takes a couple to lose a db when using a PL-259 at 52 ohms.It's not so bad with N connectors at 50 ohms but most people don't use them but they are far better all around & well worth the price.
SIX-SHOOTER
W4KVW
The loss on a good, properly installed pl 259 is very little at 30mhz and below.
Even at 440 mhz it's like 0.1 ( 0.09) db on a network analyzer.
259's get a bad rap that they don't deserve.
73
Jeff
Even at 440 mhz it's like 0.1 ( 0.09) db on a network analyzer.
259's get a bad rap that they don't deserve.
73
Jeff
Ummmmmm......OK. A properly installed quality PL-259 has negligible loss compared to a type N connector throughout the HF spectrum into VHF. I will take a PL-259 over a type N if running high power. The centre pin is much beefier. In any event that one dB at most will not be noticed.
I must Disagree that a PL-259 is a better choice.An N connector is a far better choice & they are 50 ohms,better at preventing moisture from entering the connection,& a far better connection all around.The 52 ohm PL-259 will fail far more often head to head to a properly installed N connector which has less loss across the HF,VHF,& UHF Spectrum.https://www.youtube.com/watch?v=-AARmcE7QQM Here is a good test for anyone interested.
SIX-SHOOTER
W4KVW
Does an N connector have less loss than a PL-259? Yes.
Is there enough of a difference that you will ever notice it at CB band? No.
In the video six-Shooter linked above, and in other tests I've seen, even after stringing several PL-259/SO-239's together, and in the case of the video above specifically, you still have 0.09 dB in loss across 20 of them. Further, he is using the S11 reading, not the S21 reading (I, personally, would have done this test with the both ports). So you have 20 connections, and the signal is passing through each one twice. Because of this you have to double the number of connections to get accurate average per connection. So, get a reading for a single connection, you now take that 0.09 reading and divide by 40. You get 0.00225 dB. When I did a similar test using an AIM4170 years ago, I got a similar result per connector, (although my results were a little higher, coming closer to 0.0025 dB) and I've seen one or two other youtube videos by different people showing this as well. This basically means you would have to have over 400 PL-259/SO-239 connections to get to just 1 DB of loss.
I agree with you, the PL-259 has "more loss" than an N connector, but the important part here is the scale of the difference. It is important to factor in the actual difference, which in this case is negligible. Twice as much of nothing is still nothing...
I think that the impedance change argument should also be addressed, so I'll be referencing this page which has plenty of calculations. Two lines from his conclusion.
So, at CB frequencies its well within the range of "not worth worrying over" with tons of room to spare, and if you still are worried, there is a fix that will mitigate the non-problem you are so worried over even more...
The DB
Is there enough of a difference that you will ever notice it at CB band? No.
In the video six-Shooter linked above, and in other tests I've seen, even after stringing several PL-259/SO-239's together, and in the case of the video above specifically, you still have 0.09 dB in loss across 20 of them. Further, he is using the S11 reading, not the S21 reading (I, personally, would have done this test with the both ports). So you have 20 connections, and the signal is passing through each one twice. Because of this you have to double the number of connections to get accurate average per connection. So, get a reading for a single connection, you now take that 0.09 reading and divide by 40. You get 0.00225 dB. When I did a similar test using an AIM4170 years ago, I got a similar result per connector, (although my results were a little higher, coming closer to 0.0025 dB) and I've seen one or two other youtube videos by different people showing this as well. This basically means you would have to have over 400 PL-259/SO-239 connections to get to just 1 DB of loss.
I agree with you, the PL-259 has "more loss" than an N connector, but the important part here is the scale of the difference. It is important to factor in the actual difference, which in this case is negligible. Twice as much of nothing is still nothing...
I think that the impedance change argument should also be addressed, so I'll be referencing this page which has plenty of calculations. Two lines from his conclusion.
So, at CB frequencies its well within the range of "not worth worrying over" with tons of room to spare, and if you still are worried, there is a fix that will mitigate the non-problem you are so worried over even more...
The DB
