SWR meter can I convert to 150MHz

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ybwuser

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After searching on here, I found a chap who posted a wiring diagram to make an SWR meter (only up to 1W though)

Question is, can I convert a cheap CB meter to a the 156MHz range by changing some resistors and diodes etc - or is it just not worth it for the sake of forking out £40?
 
It seems to me that if you have a good quality antenna connected via good quality connectors and good quality cable to a good radio the system should be as good as it gets.
If you are suspicious about the efficacy of any of these components, just change them.
A VSWR meter, or a bodged VSWR meter, isn't really going to tell you anything about the system that you can fix - it might confirm you have problem, but it will not tell you specifically where the problem is, so you're no further forward.
 
Your reply doesn't address my question, but you appear to be making an assumption as to why I want an swr meter and addressing a question I haven't asked.

If I connected an swr meter to your metz aerial via a 1 metre patch lead and got a reading of over 1.5:1 I'm sure you'd agree it would tell me that your aerial was not that brilliant.

I just wanted to know if anyone could say "yes, it's easy, replace the diode with a Schottky blah blah... and all the resistors with 1k ones...etc"
 
It will still have cheap meter movements, also the cheaper stuff can hide faults due to being inaccurate. I have a few meters of various qualities, but I still use my cross pointer Diawa as I can trust it.
 
Most radios put out 25watts, hand held 5w so a 1w meter would be no good. I would go to a radio ham shop, tell them what you want it for and engrave you name on the back of it cause it will be borrowed!
 
No, it would tell me that the antenna or the patch lead or the connectors were faulty; which makes my point. However, you are quite right when you say I answered a question you didn't ask - in future I'll be less presumptuous. You may wish to be more gracious when people take their time to provide you with information.
 
No, it proves my point.

I only wanted to test an aerial so an swr in the MHz range would have done exactly what I wanted. I never said I had a problem of any kind and I certainly did not say I was testing a sytem.

Your reply was about a whole system and how an swr meter was not what I wanted - well I did want one as I've pointed out.

In fact your reply was condescending, which provoked my response.

Thanks for helping me with my social graces - something else I didn't ask for.

[ QUOTE ]
You may wish to be more gracious when people take their time to provide you with information

[/ QUOTE ]

Why should I be gracious when someone provides me with codescending information I didn't ask for?

I would offer you some advice about reading posts before replying or actually answering the question posed, or tell you how to be less presumptuous or less condescending, but I am not into tellng people what to do or how to do it unless they ask.
Other people do enough of that.
 
I don't believe I said anything in my original post that would provoke such a rude response.
There is a facility whereby you can put me on 'ignore' and that way you won't have to tolerate any of my irrelevant responses. I hope this helps.
 
Its amazing to me why the subject of SWR meters provokes such hostility.

I have lately made it a policy not to become involved in questions about these things despite 40 years of designing, building buying and using the bloody things.

Perhaps it would help if people included the answer they wanted in the original post that asks the question.
 
I have been searching around on this forum and the internet for a few days for info about radios and the like.
This:
http://www.hamuniverse.com/m0uxbslimjimnotes.html
may be of use to you - it shows how to make a field strength meter (scroll down).
Don't know if it is the same as an swr, I have just discovered I have one on board and it is a great little toy.
 
It is a difficult question to answer as It really depends upon the quality if construction of the original swr meter.

It would be quite difficult for someone without experiance to determine suitability.

As one goes up in frequency the dimensions of measurement circuiry become more critical . This could add VSWR errors and give misleading readings.
I do not think the diodes would make any difference.

I personally have fitted a CB type meter in the boat and it works succesfully on both SSB HF and the marine VHF band.
It is rated up to 156 Mhz and is fairly accurate when reading SWR on both bands when checked against a Professional Bird through line kit. Not so accurate on power reading however.

The internal construction of mine is very good it has a silver plated trough and through line.

My CB meter is very repeatable and now that I know what readings to expect I am quite happy to use it as a checking device. It let's me know when something is wrong. I also know what readings to expect on the three power bands at different frequencies.

The answer is it may not give absolutely accurate readings but they will be repeatable. Look at the claimed frequency range and if possible open it up and see if it is silver plated - this will give an indication of the possible quality.

Iain
 
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