Hi all, I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike
I've built several out of chip resistors and junk parts. I have one that works well up to about 8GHz. Great for testing antennas. That's what's inside a Telonic Rho-tector (which can usually be found on eBay for cheap). A few models go up to 2.4Ghz.
You'll also *might* need a microwave load or three. 50 ohms for a reference, but also some other known values for calibration.
The problem is that you'll need an RF sweep generator to use this effectively. It's also not a VNA (vector network analyzer) so it won't tell you if any reactance is capacitive or inductive.
I think you mean HP8753B NyetWork Analyzer. $3500 for the A version (used). $13,000 for the D version. You must think I'm getting rich answering questions on Usenet.
Not too horrible prices. Thanks.
Congrats and I'm jealous. I've seen the test equipment pile in some of the local cell sites. One site has a rack of dedicated "monitoring" equipment that is powered on, but rarely used. My guess is about $100K+ slowly depreciating. Another site has two almost identical HP8920B service monitors just sitting there, owned by two of the cellular companies. I've been told that at one point, there were three, but the third one went away after an upgrade.
That's what computer control is really all about. Using a real keyboard is sometimes easier than using the front panel.
My taste in test equipment is towards cheap because I don't currently have a paying project to justify (and deduct) the capital equipment expenses. If I need it, I try to borrow it first. If less than 3 months, I rent. If more than about 6 months, I buy (used). If in between, I agonize. Meanwhile, what I have is starting to look like museum pieces:
Those are rather dated. I also have some new test equipment. Updated pictures when I have time.
Jeff Liebermann wrote in news: firstname.lastname@example.org:
I did mean that.
To be honest...that's why I posted !!!!!!! Of oucrse you know it's not mine, but the company I work for.
There's nothing wrong with old test equipment, and as a matter of fact, the new SA is a modern digital one, but not the one I wanted. I wanted the boss to buy the 20 year old analog Tektronix SA...one with a scope section and then other sections plug in depending on what you need.
The response time on the old analog one was much faster.
7L13 or 7L14? That's the only Tek plug in models I recall. Also a TR502 tracking generator. I only played with these for a short while and don't really know much about them.
I kinda prefer HP (for no obvious reason other than familiarity).
Yep. You can also take them out of calibrated sweep mode and do all kinds of nifty tricks that are difficult, illegal, or impossible on the computer controlled SA's. I'm debating the merits of buying a
10Ghz plugin for my HP140T SA, or just getting a new SA.