Sorry Same old aerial question

This is the place to discuss any general CB radio related topics. Getting started, installations, operation etc.
original45
Radio Addict
Radio Addict
Posts: 694
Joined: 31 Jul 2013, 21:11
Call Sign: 45

Re: Sorry Same old aerial question

Post by original45 »

Stick the radio on Saturday evening from 7 pm 27.585 usb. You should hopefully hear some chatter as several in Wales join in on a regular net I believe.
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

original45 wrote: 10 Sep 2020, 16:40 Stick the radio on Saturday evening from 7 pm 27.585 usb. You should hopefully hear some chatter as several in Wales join in on a regular net I believe.
Will listen out but i think that Net is South i am North Wales but thanks anyway.
wa10
Top Poster
Top Poster
Posts: 1283
Joined: 19 Feb 2008, 00:37

Re: Sorry Same old aerial question

Post by wa10 »

it should be a tight fit, a clearance fit is no good for unidirectional grp tube, you want an interference fit you have to twist in the opposite direction you wrapped the tape,

if it pushes in its too loose & you will have to take the slack up with the hose clamps,

unidirectional grp cannot be crushed much at all before you hear the clicks & crackles as the linear fibers start parting,
its best to not crush it at all,

good luck with the wind.
W8JI
"An antenna with a poor ground using few radials cannot have a support mast grounded to the radial common point (at least it shouldn't if designed properly) There is no exception to this!
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

I had to do exactly that "twist in the opposite direction" to get it to go in.
Put 2 or 3 turns on at first but no chance so took some off.
But like i said they where not a slack fit to start with but they where a tight fit with the tape.
Thanks.
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

Well the wind got up last night and still blowing and it's not winter yet so a lot stronger to come but it's bending well.

Think i will have to guy this aerial after all.

Problem i have is i can only guy it on 3 points fairly equal points at that.

Anybody think this will work.
User avatar
The Collector
Legend
Legend
Posts: 6912
Joined: 23 Jan 2010, 19:26
Location: Bristol-ish

Re: Sorry Same old aerial question

Post by The Collector »

3 will suffice.

Get the guys running from the first joint from the top and it shouldn't move much at all. From the second, you'll gave a bit of swaying but still better than it being un-guyed and acting like a fishing rod with a Blue Marlin on the end ;)
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

Just got a new toy to test the new aerial.
This is the SWR close to 555 and drops to 1.01 at around 26.000.
I dont go on the uk fm so not bothered about it going up the higher i go up the frequency.
Opinions welcome.

Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

The Collector
Yes that was my plan from the top joint.
Ordered some stuff to do it on Friday so hopefully it will come tomorrow sometime our post can come at 4.30pm but normally 12.30/1pm.
What happened to the hot weather i read about for today and the next couple of day's.
wa10
Top Poster
Top Poster
Posts: 1283
Joined: 19 Feb 2008, 00:37

Re: Sorry Same old aerial question

Post by wa10 »

Alan Pilot

earlier you said you can't understand the tuning chart, you must have the 1/2wave which needs cutting for where you intend using it most,

1/2wave Gain-masters don't have the bandwidth of the 5/8wave, no stub & top coupling capacitor to give a low wide vswr curve,

the 1/2wave will handle more FM power than the 5/8 if you tune it for minimum vswr.

5/8wave GM has a wide low vswr curve with a double dip in the curve like other top coupled antennas such as the X-pole,

highest vswr for the 5/8 across the cb bands is right around ch19 ukFM.
W8JI
"An antenna with a poor ground using few radials cannot have a support mast grounded to the radial common point (at least it shouldn't if designed properly) There is no exception to this!
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

I should have said i got the 1/2 wave before sorry but i went for the shorter due to neighbors plus a council run home just over the wall.
I am happy with the swr as it is i didn't cut anything off just fitted the brass end to the end.
It will be coming down again to sort out the guying situation and i might just shorten it an inch or so.
But as for the tuning chart goes it made some sort of sense but the diagram showed where to measure it from and that made no sense at all well to me that is so i just put it together and up it went.
Being disabled don't help as i get frustrated when i can't do stuff like i could at one time does my head in as i have to stop and rest but you guy's help with that as i sit and have a look on here for some rest time.
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

SWR is 2 at 28MHz and then below until it hit's 2 again at 25MHz so happy with that and might not cut any off.
User avatar
The Collector
Legend
Legend
Posts: 6912
Joined: 23 Jan 2010, 19:26
Location: Bristol-ish

Re: Sorry Same old aerial question

Post by The Collector »

Just get it lowest where you'll be using it most of the time ;)
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

The Collector wrote: 13 Sep 2020, 15:33 Just get it lowest where you'll be using it most of the time ;)
Going to cut a bit off when it comes down in the next couple of day's try for 1to1 where it is now ;)
User avatar
The Collector
Legend
Legend
Posts: 6912
Joined: 23 Jan 2010, 19:26
Location: Bristol-ish

Re: Sorry Same old aerial question

Post by The Collector »

Just take it steady and take off a few millimetres at a time ;)

Been and collected a 20ft alloy pole today, so I can carry on with some more of my crank-up mast design. Good price too. Only had to wait about 6 months because of Covid!
Just need a slightly thinner 3 or 4 metre one next (this place only sells scaffolding size in alloy).
You do not have the required permissions to view the files attached to this post.
Alan Pilot
Regular
Regular
Posts: 87
Joined: 21 Dec 2019, 07:24
Call Sign: 163ct220

Re: Sorry Same old aerial question

Post by Alan Pilot »

Well it's got guy lines on it now so feel a bit happier with it.

Cut 1.5cm off the end as well and got the SWR where i want it 1.02 on 27.555 and 1.12 on 26.555.

Just need to fasten the anchor end's permanently but that will do tomorrow.
Post Reply