Using an Oscilloscope to Check Your (Transmitted) Signal

N2NOV had posted that Tektronix now has a Youtube channel with videos on how to properly use an Oscilloscope.  Many years ago, Tektronix published a good free PDF, The XYZ's of Oscilloscopes. It was
good but a little dry compared to a video presentation.

Well equipped radio operators have a special type of dedicated oscilloscope called a service monitor which allows viewing your transmitted signal, by tapping the radio frequency (RF) from the transmission line. Recently I came across a Youtube video that showed how to build a very simple RF sampling circuit that would allow using a common oscilloscope to monitor the RF output of your transmitter (transceiver).  While this won't do everything that a dedicated service monitor would do, it's a pretty cool way to check your signal if you only have an oscilloscope.  The RF sampler circuit described should be less than $10 in parts.

Personally I find this sort of thing to be very cool.  Even if I had an unlimited budget for buying equipment. I don't have the room to store it in NYC.

• How to Use an Oscilloscope
• Tektronix Youtube Channel
• How to monitor your Ham Radio Transmitter using an Oscilloscope

Note: This will only be useful for monitoring AM and SSB transmissions. I hope to come across something not too difficult to build that would be useful for looking at the output of an FM transmitter like the type most commonly used on VHF and UHF.

Good Tutorial on TCP/IP Diagnostics using Traceroute

MTK, just sent me this today.  It's a presentation and paper by Richard A. Steenbergen, from 2009 that covers the finer points of diagnosing TCP/IP networking problems with Traceroute.  It looks like it was originally presented as a tutorial at NANOG.  Why am I posting this?  If you tried to google "traceroute tutorial" you'd get tons of fairly lame overviews that show some traceroute output and attempt to explain it. 

To quote one of the intro slides:

Few people are actually skilled at interpreting traceroute.  Most ISP NOCs and even most mid-level engineering staff are not able to correctly interpret a complex traceroute.  This Leads to a significant number of misdiagnosed issues, false reports, etc, which flood the NOCs of networks world-wide.  The false report rate is so high that it is almost impossible to
report a real traceroute-based issue through all the noise.

There is a lot of nitty gritty practical details in here. Even if you rarely use traceroute, you'll learn a lot from this. This is one of those rare, good presentations and papers to file away so you can refer back to it and hopefully use to enlighten others.

• Presentation: A Practical Guide to (Correctly) Troubleshooting with Traceroute
• The Paper: Traceroute, PDF, 20 pp
• NANOG listing for the tutorial, includes a link to a .WMV video 

Hope This Helps.

Hams, Yahoo Groups and private message archives

Someone asked about learning the Yaesu VX-8 on one of the mailing lists I subscribe to. I sent the following response which has got general advice about Yahoo groups which seem to be popular with ham radio people. The most important bit:

If you are a member of any active Yahoo group that has useful information to share, consider lobbying the group's owner to make the message archive public.  It makes the information more accessible and should cut down on some of the redundant questions.

Please spread the word. The more information that is easily searchable the more we all benefit. 

Here's the original response:


I have a Yaesu VX-8DR and would be happy to answer questions about it.It has a lot of features and the manual isn't always as straightforward as it could be. I've learned a lot from reading the VX-8 Yahoo group for the last 2-3 years.

I suggest joining the Yahoo VX-8 Group, and then reading some of the old message traffic.  Many of the questions about the radio have been asked and answered since it came out.  Also check through the files and links section of the yahoo group.  There are some documents people have put together on working satellites, APRS and the ISS, etc.

Yahoo groups seem to be pretty popular for hams and there appears to be one for most popular radios.  If you have, or are considering purchasing a particular radio, check to see if an active yahoo group exists for it.
Then join it and look through the message and file archive.

Unfortunately one drawback of Yahoo groups is by default the message archive is only accessible by  members.  This means Google and the other search engines can't index the information stored in them.  The result is it's harder for you to search for answers to your questions.  You'll need to go to the Yahoo group and use its search function to look for answers.  (I still recommend using google to search for answers that might be available on the open internet in blog posts, open forums, etc.)

If you are a member of any active Yahoo group that has useful information to share, consider lobbying the group's owner to make the message archive public.  It makes the information more accessible and should cut down on some of the redundant questions.

Here are a few groups that I belong to that I'd like to get opened up:

• Wouxun_KG-UVD1  Wouxun KG-UVD1 (2)(3)(6) and KG-UV920R
• Yaesu VX-8R
• Yaesu FT-857D
• Uniden BC346XT
• Uniden BCD396T
• Uniden BCD396XT

There's a lot of knowledge locked up in those groups.

Hope This Helps,
--Rob