Shouldn't my SWR be high or am I an idiot?

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beamin

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Ok so for an experiment I plugged my 7 watt 40M radio into this SWR meter I just bought. Radio to SWR meter is through a proper cable. But to see how much impedence changes matter I set up what you see. A test lead into the u239 and then alligator clip to BNC, first with ground from barrel to barrel then from barrel to that little metal rod that stick out.

All that happens when I hit transmit when set to 10W range and REF switch is a small jump on the right side dial then the needles sit on the bottom, and when the switch is set to PWR the right needle jumps all the way to the end then they sit on the bottom.

Shouldn't I get some sort of reading?

Whats the purpose of the little rod that screws into the SWR meter, I thought it was for a clip on ground. I have never used this meter before so I don't know about it, it was 22.00 News off walmart.com (didn't realize it came from walmart).

Whit cable goes about 50' to a 11:1or 9:1 balun then to a 60some foot long wire that I have been using as an antenna that seems to have been working so far. The radio last I checked was putting out a good signal when I used a separate SDR and antenna to look at its signal.
 

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ko6jw_2

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I would never suggest that someone is an idiot. However, you might want to read the instructions for this meter. The rod on the side is a short antenna for use as a field strength meter. It has nothing to do with SWR measurements. You might want to get an F to PL-259 adaptor so that you can plug the feed line directly into the meter. The clip leads cannot be doing anything good. You seem to have an end fed half-wave antenna and although you are using a balun, an antenna tuner might be needed. Let us know how things work out.
 

zz0468

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There may be some sort of RF power fold back taking place, something the radio does to protect itself in a high VSWR condition. Typically, you see a quick burst of power, then it drops. Not knowing what the radio is, I'm just making an educated guess.

Just a side note, you're going to want something other than a random wire for a transmit antenna if you want good results.
 

beamin

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Well I'm partially an idiot. I had it backwards and remembered that SSB needs sound to put out power.

So how does the Cal knob work? At one end the right needle is all the way to the right at the other end of the knobs range it barely meters. How do I know where the actual reading lies?
 

beamin

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There may be some sort of RF power fold back taking place, something the radio does to protect itself in a high VSWR condition. Typically, you see a quick burst of power, then it drops. Not knowing what the radio is, I'm just making an educated guess.

Just a side note, you're going to want something other than a random wire for a transmit antenna if you want good results.
Oh the wire is cut to a specific length that I figured out. I just can't remember what that length was. Should work like a beverage antenna.

The radio is a bitx and the spike was when it caught the click of it coming on. Then no power because it had no sound to transmit. I found blowing on the microphone makes a nice steady signal out of it, but now I don't know how to set the "cal." knob on the side. I tried to find a dip or peak by turning it one way or another, if that makes sense but seems to be 0 needle movement at one end and full range as the knob hits the other end.


EDIT:
The meter didn't come with any instructions so I was guessing that most of these SWR meters had similar operation.
 

n9mxq

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Standard SWR meter instructions.
Set Switch to CAL (on your meter FWD)
Transmit dead key on AM or CW
adjust knob until needle is at CAL (Set on your meter) mark on the sweep display. Unkey
Set switch to SWR (On your meter REV)
Key up once again on AM or CW and the needle shows your SWR.
 

majoco

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You can't go joining your RF cable to the VSWR meter with clip leads, either on the input or the output to the antenna - you can use adapters but every adapter spoils the VSWR. You need a F-type to UHF adapter to join your transmitter to the RTX socket and a similar adapter to go to your antenna - I can't see what sort of antenna you are using there and I don't understand why you are using RG6 and F connectors to transmit through a nominal 50ohm system for transmitting - or don't you know if the antenna is resonant on 40m. I take it that you do have a ham ticket.
 
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jwt873

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Whit cable goes about 50' to a 11:1or 9:1 balun then to a 60some foot long wire that I have been using as an antenna that seems to have been working so far.
If the white cable is the feedline going to your balun and 60 foot long wire antenna, then you have the meter connected backwards.

Looking at your photo, you have the white wire connected to the RTX connector on the meter. (R = receiver TX = transmitter). That's where you're supposed to connect the output of your radio.

The antenna goes to the SO-239 connector on the ANT side. (ANT = antenna).

And as others have pointed out.. Connect the meter properly with coax and the correct connectors. You won't get any meaningful measurements with all the unwanted capacitance and inductance that the loose wires will introduce.
 

SCPD

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OMG ! Beamin- that is a Mare Nest !
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You are hardly an idiot, maybe a trite misdirected- but Hey- that's how you learn.
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Instead of trying to talk you thru SWR meters, maybe pictures will do it better--
I just did a 1 minute flow thru of YouTube.. there is Plenty! of information on how to use these meters.... Videos Galour!.... not to mention all the stuff that comes up on regular Google searchs.

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Do you have an ARRL Handbook ? I'd highly suggest one if you don't.
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And by all means- Keep experimenting! The only bad questions are the ones unasked.
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(Oh, BTW, that little side port on your SWR meter is for Field Strength measurements-- The way I think you have it hook'd up is-- for lack of better technical terms: not right :) Look at that Handbook )
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Good Luck Guy
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..........................CF
 

RFI-EMI-GUY

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Ditto on the ARRL Handbook!

Go to your local library and check one out, or get one from e-bay. Any year from 1980 on will do! The basics haven't changed much. You will get a lot of opinions on the interwebs, but the ARRL handbook is the bible.
 

paulears

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The knob is used to adjust the forward needle to the maximum mark on one meter, and then the other one indicates VSWR.

Personally, I suspect you're pulling our legs - You wanted to to see how much impedence changes - which suggests you're aware of at least the word and probably it's meaning - then you use test leads in a bizarre way. Clearly, every connection is coaxial for a reason - radio, meters, antenna, cable - using test leads and crock clips is surely a big question?
 

RFI-EMI-GUY

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The knob is used to adjust the forward needle to the maximum mark on one meter, and then the other one indicates VSWR.

Personally, I suspect you're pulling our legs - You wanted to to see how much impedence changes - which suggests you're aware of at least the word and probably it's meaning - then you use test leads in a bizarre way. Clearly, every connection is coaxial for a reason - radio, meters, antenna, cable - using test leads and crock clips is surely a big question?

I wanted to jump through the screen and say, stop that, you will burn it up!

Hey we all make mistakes. I burned up a pricey HP step attenuator in the lab once. I had a prototype 110W VHF radio on the bench, looking for spurs, had a suck out filter, thought I had proper isolation. Well it was an early Monday morning fiasco, no coffee yet. Cables were switched.

I could not figure out why as I was switching in more attenuation the signal on the spectrum analyzer was climbing. Its just not supposed to do that!

Then the odor of ohmite.....

Thankfully the spectrum analyzer did not receive the full brunt of my mistake, otherwise I would have had a lot of splainin to do.
 

zz0468

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Thankfully the spectrum analyzer did not receive the full brunt of my mistake, otherwise I would have had a lot of splainin to do.
I did that once. The explanation was easy, and resulted in no follow-up questions or discipline: I just said "I screwed up". Only, that wasn't the exact word I used. :p
 

paulears

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You HAVE to make mistakes to learn from them. Nowadays, too many people read the net forums, buy the gear, plug it up and are happy - not just radios, but all the other hobbies that use gadgets. Trouble is, many are happy with a system that performs less well than it should, because they never had a system work badly enough to spend time working out why!

I bought a radio in Germany in the 70s, so did my mates, and we brought them back here and wrapped a bit of wire around the aerial tip when it was just poking out the radio, rather than managing a damn great thing about 6 ft long. We dangled the bit of wire out of the window and when travelling together, we could chat to each other. At a custom car show at Santa Pod, we were amazed when other people seemed to be doing the same thing somewhere on site, so we found them and discovered what we had were things called (we thought) CD radios. These people had things like Mustangs, Stingrays and Camaros - and all had proper aerials and most importantly, proper radios. I opened my radio up and fitted one of those weird screw on sockets I got from Radio Spares (now RS). I ordered from America, one of these antennas, and the distance between radios increased, when my friend did the same, it went up again - 1W went a long way. Sometimes we even heard real Americans! Every little tweak made differences and back then we were on our own - no internet and nothing in the library. One day, somebody parked next to us with a different antenna, and explained what we had, how we should probably keep it a bit quiet as it was illegal here, and he invited us to the local radio club - where we fitted in. Lots of people like us. It took a nearly a year to get up to speed on the technical stuff, then six months to get an exam slot in London, and then we got a licence, in 1980. We learned things by tying them out, dumping the bad, doing more of the good. Now it's changed. You don't need to do this any more, you get the licence first, then buy the gear and are totally unprepared for when it doesn't work.

The scanner owners have it even rougher - they can get the info to stick things in to the radios, but are really stuck because they don't have any of the knowledge to make it work. If you look back to your physics at school, with batteries, lightbulbs and switches, your knowledge tells you that many antennas should not work - they are a short circuit - which they are, to DC, but school physics went no further. Perhaps we should not be surprised at somebody using ready made croc clip cables being used - it's what I did with my 1W CB!

Personally I really don't see any difference in status between any radio user - the only thing that makes any difference is in knowledge. Somebody who used to stick AM transmitters in trawlers knows a lot more about them than I do, and I know very little about microwaves - where most home made stuff seems to be plumbing!

All the different groups tend to be a bit snobbish - better than them, but annoying not so good as them, and that's rubbish really. Each group has good and not so good people. I wish they'd kind of share - the people who dabble with PMR446 frequencies often have no clue other people have gone before. They might not even know that the essentials that can help them have been done before. The CB people are experts in just their little bit of HF, when new hams who now have access to this part of the HF world are clueless. People reinventing things, duplicating things, and often slagging each other off. Clearly all the groups have some total idiots in their number - but I've not found that ever the norm. Idiots are everywhere.

Perhaps somewhere there is a Radio Club - not a 'something' radio club, just a place where radio enthusiasts can feel at home with none of the old issues. That would be good. I might even join!
 

prcguy

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If the meter is eventually connected the right way and calibrated, the clip leads are not a big deal at most HF frequencies even up to 27MHz CB. If you have all the correct connectors and do an SWR reading on say a 40m antenna, then unscrew the antenna cable and extend it with a pair of clip leads connected to the meter it will usually not change the reading due to the clip leads being such a small fraction of a wavelength.

At CB frequencies you can make a tight twisted pair out of the clip leads and it will have minimal effect on the antenna SWR when they are in line. I think the OPs biggest problem was the meter being used backwards and connected wrong.
prcguy
 

wrath

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The only bad question is the one you learn by smoke signal .

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I still have my Miller Grid Dip Oscillator and coil set, in addition the matching 50 Ohm bridge. You would select the proper pickup loop for your desired frequency range, plug the correct coil for the GDO and tune your antenna to 50 Ohms. Worked then still works now. Showing my age, licensed HAM 50 years!
 

wrath

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Well you got me beat by 24 years then , but I would love that rig , I remember as a kid people loading up fire escapes and wrought iron fences as antennas .The good old days of the 70's.

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RFI-EMI-GUY

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I still have my Miller Grid Dip Oscillator and coil set, in addition the matching 50 Ohm bridge. You would select the proper pickup loop for your desired frequency range, plug the correct coil for the GDO and tune your antenna to 50 Ohms. Worked then still works now. Showing my age, licensed HAM 50 years!

I had a GDO (Eico?) I built from a kit while at United Electronics Institute. Later a freind borrowed it - for several months! When I finally got it back, the tube was weak and oscillating poorly. I asked him what he did with it. He said he jammed his neighbors loud TV the whole time.
 
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