• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

need input weather 1/2 or 5/8 wave

1iwilly

Sr. Member
Dec 7, 2008
811
587
103
62
trying to decide on the Sirio tornado 27 or the Sirio GPS27 5/8 wave both antennas are under $100 at Walmart on line or amazon
my Sirio gps27 1/2 wave broke today
 
  • Like
Reactions: Marconi

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.
 
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

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.
 
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
 
  • Like
Reactions: NZ8N
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

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.
 
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.

The down side of an incorrect impedance are either not worth worrying about or are easy to compensate for at frequencies less than 500MHz.
Also you can buy SO-239 connectors with a mostly air dielectric. The large center pin with a relative dielectric of something like 1.3 would raise the impedance to 46 ohms and be much less of an issue.

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
 
humm 50 years owning cb and ham radios.only pl 259 problem ive seen is from my removal of radio n install.if i had to leave a company truck at shop i removed radios and i have screwed up a few pl 259s
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Wildcat27:
    Hello I have a old school 2950 receives great on all modes and transmits great on AM but no transmit on SSB. Does anyone have any idea?
  • @ ButtFuzz:
    Good evening from Sunny Salem! What’s shaking?
  • dxBot:
    63Sprint has left the room.
  • dxBot:
    kennyjames 0151 has left the room.