Field Strength Meters & Microwave Diodes

Novilio · 07-24-2002

I spawned this as a new thread to avoid some serious thread creep, but sparafina pointed us to this homebrew field strength meter for 2.4 GHz:

http://www.mrx.com.au/wireless/TestGear2_4ghz.htm

The author didn't cite a specific microwave diode, but the case style looked familiar, so I went out into the (sweltering) garage and dug around until I found the diodes shown below. Some are unmarked; some are JBYI-1N23C units, and they have the word "microwave" printed right on the side, God love 'm.

Nothing on the 1N23C in any of my semi references, and if anybody out there knows what their useful frequency range is (Mr. WLAN?) it would be good to know, especially since the 1N23C is available from several places on the Web for just a couple of bucks.

And for those who have worked in microwaves for awhile, answer me this: Is any diode in a case like the one shown by definition a microwave diode? (Just like any device in a TO-3 case is by definition a power device.)

--73--

--Novilio

highfrequency · 07-24-2002

These are old Microwave crystal diodes. They were once popular in the military in the 60s and 70s for old microwave radar detectors/receivers. I once bought a bunch of surplus test meters that specifically test these diodes and still have several in the garage gathering dust. If you want one, give me a shout.

I'll have to dig into my old catalogues in the basement to determine the upper frequency limit, but I think that it is somewhere around 10 GHz.

The case type gives it away, it is a microwave crystal diode. The part number will tell you something about the frequency range.

highfrequency · 07-26-2002

I had to dig really really deep into a pile of old catalogues from Harris corporation but it looks like you can go up to 12 GHz with a 1N21 or 1N23 crystal detector. 1N26 and 1N78 detectors go up to about 18 GHz and the 1N286 to 26.5 GHz and the 1N53 to 40 GHz.

All of this assumes the crystals are correctly installed. Shouldn't be much of an issue using the 1N 23 in a 2.4 Ghz (802.11b) or 5 GHz (802.11a) field strength meter.

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07-24-2002	#2 (permalink)
highfrequency Registered Member Join Date: May 2002 Location: Vancouver Posts: 22	These are old Microwave crystal diodes. They were once popular in the military in the 60s and 70s for old microwave radar detectors/receivers. I once bought a bunch of surplus test meters that specifically test these diodes and still have several in the garage gathering dust. If you want one, give me a shout. I'll have to dig into my old catalogues in the basement to determine the upper frequency limit, but I think that it is somewhere around 10 GHz. The case type gives it away, it is a microwave crystal diode. The part number will tell you something about the frequency range.

07-26-2002	#3 (permalink)
highfrequency Registered Member Join Date: May 2002 Location: Vancouver Posts: 22	I had to dig really really deep into a pile of old catalogues from Harris corporation but it looks like you can go up to 12 GHz with a 1N21 or 1N23 crystal detector. 1N26 and 1N78 detectors go up to about 18 GHz and the 1N286 to 26.5 GHz and the 1N53 to 40 GHz. All of this assumes the crystals are correctly installed. Shouldn't be much of an issue using the 1N 23 in a 2.4 Ghz (802.11b) or 5 GHz (802.11a) field strength meter.