This short video shows a very simple way to hook up an oscilloscope to use it as an RF Signal Monitor to observe the RF envelope from your ham radio transmit…
Video Rating: 5 / 5
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what a great way to monitor your signal. Most ham operators already have
antenna tuners. What type of scope would you need. Would a 5MHZ scope be
adequate or would you need something better ?
When you can do a video on differential probes and their use. Thanks
Yep – that usually works well too!
I appreciate your comments. I hope I stressed the caution strongly enough.
I have used this method on five different tuners in the past with no
problems, but you do have to take care to use the right switch positions.
Very helpful, I have an older 10 Mhz scope and because it was that, I
didn’t really consider it for HF since I didn’t think it would work on the
upper bands very well but after watching your other videos showing how they
still do work much above the rated freq, just with a lower amplitude
response and guess as long as I could see what the signal looked like, that
is what I am concerned about, so might play around with that sometime,
thanks, all your videos are very informative.
very cool
I found it very useful when setting up PSK31 levels as shown in the earlier
video.
Ruby – I just uploaded a video on differential probes and their use.
Another cheater way to do this is to take a few turns of wire around the
coax feed to the antenna.
I never would have thought about doing that……. A stellar idea! RW
1ms per division, as shown in the bottom of the scope CRT.
Your videos are always excellent and well presented but I’m not so keen on
this sampling method because of the risk of damage. I know you warned about
this more than once but I think it’s a bad method to advertise to others
because it is so vague and tuner specific. Your other RF sampler videos use
much better defined and safer methods. RF damage to test equipment is
always a worry and I use various methods to minimise risk such as diode
limiters and even RF fuses inline with the limiter.
That neat ng9p
It is on my list of videos to do in the near future – stay tuned!
Almost anything would work. Even a 5MHz scope will still have some response
beyond 5MHz. It might run out of steam at the upper end of the HF range,
but it certainly can’t hurt to try it. I’ve used a 10MHz scope in the past
in this way, and it worked great over the entire HF band. Give it go!
Absolutely useless for any practical purpose.
Interesting. I think I would put my real outputs as 1 and 2. Without
switching by the scope. Thanks I think I will try this or something
similar soon.
Excellent, i bought an old scope a few months ago with the intention of
learning how to use one, but when i realised i couldn’t monitor my own
signals with it, i kinda left it on a shelf. But now you’ve solved my
problem for me, this is my project for tomorrow. Love your video’s and as
you can probably see, i’ve subscribed to your channel.
73 Jeff M1BCM
Bit safer… if do not have a purpose made sampler (I have made and used
one the simple resistance samplers you show in the video) why not just wrap
one end of the scope input feed about the TX RF cable?
Take a simple BNC (RG174 or RG58 (thinner so flexible) patch lead, one end
you connect to the oscilloscope channel the other strip back the braid for
4″ or so and just wrap the centre about the coax, you should see a signal
on the scope when you TX. This way you will not TX into your scope and you
will still be sampling some of the RF going to the dummy load or antenna.
We have all seen or used a clip on ferrite core over a feed line, you have
asome wire wrapped about the ferrite and to a uA meter this indicates RF
going through a feedline… this is exactly the same principal.
Despte the warning I can still see someone if careless might put 5w or even
500w into their scope 🙂
72
Dom
M1KTA
A reason to take my scope out of the shed and give my shack that high tech
cool factor!
I’ve done the same thing w/o a tuner. A loop of wire a few feet in
diameter works well. Mine consists of several test clips connected together
and draped over the curtain rod. I also have several turns of wire wound
around the coaxial feedline that does the same thing.
Also, I have my Tektronix 2236 (100 MHz) set up with “Normal” triggering
and the trigger level set /just/ above zero. Until the ‘scope sees some
signal, there is no display. That saves the phosphor coating inside the
front of the CRT, and extends the CRT’s cathode life.
how do you monitor the in comming rf?