3 ms·
Heh, I just wrote a blog post this weekend where I tested, among other things, the loss of some coax cables: https://tomverbeure.github.io/2023/05/06/HP-11720A
by tverbeure 3y ago
Heh, I just wrote a blog post this weekend where I tested, among other things, the loss of some coax cables:
https://tomverbeure.github.io/2023/05/06/HP-11720A-Pulse-Modulator.html#cable-loss-measurements-with-hp-432a https://tomverbeure.github.io/2023/05/06/HP-11720A-Pulse-Mod...
My results are much worse, with a minimum of 2.5dBm, but I'm measuring frequencies that start 1.5GHz and that go all the way up to 20GHz.
It'd be interesting to redo these measurements at the frequencies of this blog post. I think they're doing the measurements at 28MHz?
- GeorgeTirebiter 3y agoHi, I apologize for being the RF pedantic, but did you mean "2.5 dB"? dB is a ratio; "dBm" is just one way to declare a given power, in this case because it is referenced to 1 millwatt (the 'm' in dBm). Ergo, 0 dBm = 1 milliwatt; 30 dBm = 1 Watt, etc. I hope you were very careful with your fixturing going up to 20 GHz; poor fixturing can be masking the cable's true performance.
- tverbeure 3y agoYeah, I meant dB. And, no, I wasn't very careful at all. This was done with an uncalibrated 30+ year old sweep generator with questionable attenuator, a 40 year old power meter that's only rated up to 10GHz, AliExpress connector adapters, and an assortment of coax cables that I took from my stack. At 20GHz, it shows a trend at best. (I wrote as much at the bottom of the blog post, but I forgive you for not reading that far!)