SWR/Reception

Hoiya all, hope all is well.

I have a query with my recently installed homebase set-up which consists of an expanded President McKinley plus a Thunderpole 5/8 wave Hi-Gain aerial mounted on my chimbley pot. SWR was spot on 1.0 though now the readings fluctuates as follows on muppet channels :-

Ch 1 1.0, 1.2
Ch 20 1.0, 1.4, 1.6
Ch 40 1.4, 1.6, 1.8

I can receive local muppets within a mile or two radius and thats it, though have picked up as far afield as Belfast, Hamburg, Poland & Italy on other channels. Is my SWR ok or do I need to do some tweaking? 

Last time I used a CB was back in the 90's and the hobby seems to have changed so learning whats what.


Thanks in advance 

Hello Hagar,

Did you get this sorted out? My first port of call would be all the connections from the radio to the antenna and to make sure the antenna itself. Of water gets into any of the connections or the antenna you can get the fluctuations you describe. Let us know how you're getting on.

Best 73 Gary.

Hoiya Gary

I'll get them checked out. I meant to put some amalgamation tape around the jubilee clips and connections. Will get that done and checked out too.

73s

Hagar

Hello Hagar,

Yes definitely get it all sealed up. You can also put vaseline around the threads of the PL259/SO239 it really works wonders. Also check that the sections of the antenna itself haven't slipped a little.

Best 73 Gary.

Hoiya Gary and anyone else.

Haven't managed to get aerial looked at yet ( I can't get onto my roof ) though out of curiousity I checked the SWR on AM, USB & LSB and it was over 3.5

Whats the best way to check the SWR on a multimode radio so the SWR is even throughout all the different bands?

Any advice is much appreciated.

Poikey wrote:

...
Whats the best way to check the SWR on a multimode radio so the SWR is even throughout all the different bands?
...

Usually in the middle, but most aerials will only do 2Mhz or so (200ch), shorter ones less. I've set mine to 27.500 for the lowest swr (I use mostly UK & sometimes mid), below 26.500 or above 28.500 and my swr starts to go over 2:1 so double low is out for TX but OK for listerning. What bands do you use? Set for the middle and you'll be about right. You won't get 'even swr' on all bands, not even close, so pick the ones you use the most and set for those.

Only use am or fm when checking your swr.

Thanks Mitch & Alan

At moment mainly listening to UK and do a scan on most channels that the rig has though perhaps ought to narrow it down to what bands I listen too/use.

Regarding SWR, will it be the same on FM & AM?

Bear in mind I'm new to this hence the questions

Yes the swr will be the same in any mode but you need a constant carrier to see what it is so am or fm.
The antenna is what you are measuring well the reflected power so if the swr is high you have more power coming back down the coax.
Sorry not good at explaining things very well but that should cover it mostly i think.

So, if I've understood this correctly, check SWR on 26.800 ( ish ) AM & FM as I intend using UK + EU CB & Freeband then I shouldn't be far out.

Yep am or fm don't need to check it on both.

Will give it check a bit later. Much appreciated

Your more than welcome.

Righto. Just checked the SWR with a meter and got the following readings :-

27'805  1.1

UK Ch 1  1.5
 "   Ch 20 1.6
 "   Ch 40 1.9

When I checked the SWR with the built in SWR meter I had the aforementioned fluctuations. What has also been noticed is my modulation is very quiet, can barely get out or receive though have picked up transmissions from far afield. I've yet to get someone to go onto my roof to check connections ( it's only just been installed in the past week or two ) . I also have the potential of putting an extention coax in so I can raise the antenna.

All advice & thoughts greatly appreciated

27.805 or 26.805.
If the latter then the swr looks ok.
Modulation some radio's need a power mic not sure about your's not had one.

Quote :

... What has also been noticed is my modulation is very quiet, can barely get out or receive though have picked up transmissions from far afield...

Those McKinley's are quiet on the tx mod, they're set for euro specs @1.8khz, UK specs are @2.5khz deviation, it's a known issue. They can be turned up inside though, if you know what you're doing, or you know a rig doctor.

Someone has fat fingers! 26.805

I wouldn't know how to turn the rig up nor know a rig doctor. Do have another McKinley that's going into a Land Rover.
Whilst the modulation is quiet, any thoughts on reception and transmission distance?

Fat fingers? Yeah got some of those myself, lol. Comms range will very much depend on the setup and location, 3-4 miles is decent for mobile, 10-15 or so for homebase, could be less, could be more, you'll find out when you use it how good it is. Height is might as they say. A power mic might be worth it to help you get out better and be heard, but a rig tweak will do more. All you can do is try it, nothing beats experience learned from doing stuff yourself.

KP-O powered mics are the best for the McKinley but the downside is you’ll loose the up&down channel buttons on the Mike. Besides the KP-O, none of the others gave me satisfaction. The stock mic being on the quiet side is a known problem but I still can do great DX with the rig even when coupled to a boomerang antenna!

Just so happens that I've procured two. Getting antenna looked at this afternoon and see what's what!

Update.....mate went up onto the roof of my bungalow to help with SWR and raise the antenna. Got the SWR down to 1.6 then raised the antenna by a couple of foot. Checked the SWR again on a meter and it went up to 2.5 though the built in SWR meter went up to 5.0/5.2 Checked on UK Channels 1, 20 & 40. 

Being inexperienced with multiband radios, I assume that I've done something wrong.

Just raising a couple of feet should not really alter the swr, is it near anything metal btw?

Check for bad connections, water in coax etc

Yes, got a scanner aerial plus next doors TV aerial on the same chimney pot........

26ct3574 bev,if you are having theses problem I would consider getting another antenna,.y personal choice would be a gainmaster 5/8 wave lenth,the reason I say this is because it is easy to set up and once up you will have a 1.1.2swr right through all your bands,just follow the instructions  to the tea.if you can't  afford one just check that you don't have any swarf in the bottom of the antena,reason I say this is because these aluminium antennas are mass produced and do t alway leave the factory checked and cleaned,at the end of the day you get what you pay for,hope this helps as I had the same problem year ago with a venom. Antennas and that turned out to be swarf inside a antenna, good luck. Bev.