SOLD: Active Fet Probe PM 8943 -  - Page 1
Forum section: electronics / general

author: george graves
author_rank: Super Contributor
timestamp: June 22, 2014, 12:23:21 am
content: Frequency range: DC 0 - 650 MHz (-3 dB), AC 1 - 650 Hz (-3 dB).Risetime: 550 psAttenuator 1:1 Max +/- 100 V, 1 M? // 3.5 pFAttenuator 10:1 Max +/- 200 V, 1 M? // 2.4 pFAttenuator 100:1 Max +/- 200 V, 1 M? // 1.4 pFPower supply adapter included. 110 volt. Tested, seems to work great. Sold as is.$50 +$10 shipping. US only.PM me for paypal info.

author: rob77
author_rank: Super Contributor
timestamp: June 22, 2014, 01:14:30 am
content: why so cheap ? 50$ is more like a retail price of a 250MHz passive probe made in china.i'm just curious why it's so cheap

author: george graves
author_rank: Super Contributor
timestamp: June 22, 2014, 01:17:59 am
content: Well, $50 is the price. (I have no clue what it's worth. My stupidity is your gain. )

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: June 22, 2014, 01:28:23 am
content: I would be very curious to see what is inside? Looking at the photos - it is just one screw to take the cover off.

author: george graves
author_rank: Super Contributor
timestamp: June 22, 2014, 01:36:35 am
content: Sure - why not!

author: fpliuzzi
author_rank: Regular Contributor
timestamp: June 22, 2014, 02:11:00 am
content: Looks interesting... PM sent.

author: marshallh
author_rank: Unknown
timestamp: June 22, 2014, 02:26:31 am
content: I'm interested will pay ASAP

author: george graves
author_rank: Super Contributor
timestamp: June 22, 2014, 02:57:12 am
content: Quote from: fpliuzzi on June 22, 2014, 02:11:00 amSOLD

author: edavid
author_rank: Super Contributor
timestamp: June 22, 2014, 03:17:09 am
content: Quote from: rob77 on June 22, 2014, 01:14:30 amIt's a used FET probe with no attenuator tips, no spring hook, and no guarantee. I'd say George's price was in line with the (US) market. You could get a Tek P6201 on eBay for about the same price.(And a Chinese 250MHz probe goes for $25 or less, if that's relevant.)

author: rob77
author_rank: Super Contributor
timestamp: June 22, 2014, 06:34:47 am
content: Quote from: edavid on June 22, 2014, 03:17:09 amok, makes sensei didn't know the used active probes are so cheap in US, thanks for explanation. (actually i was never looking at those actives - as i have no use for them with my 100MHz scope)btw.. i searched for a US retail price of my favorite cheap passive probe.. and i was close with the $50http://www.proskit.com/test-instruments/parts/oscilloscope-probe-kit-6-250-mhz

author: fpliuzzi
author_rank: Regular Contributor
timestamp: June 22, 2014, 12:39:13 pm
content: The only FET probe that I currently have is the one I fabricated a few years ago from the info in the Elektor magazine article "Poor Man's 1GHz Active Probe". It works fairly well considering the price, but it has a fixed 10:1 attenuation and is AC coupled only.I like the fact that this Philips probe is unity gain and has both DC and AC input coupling. Also, the photos above seem to show that the device should be relatively easy to repair in the case of a 'mishap'. I'll be curious to see what circuitry is contained in the probe itself when it arrives (I just noticed one site selling a PM8943 that included 5 extra BF512 FETS for possible future repairs).Even though the 10:1 and 100:1 attenuator tips are missing, this PM8943 probe should still be a useful addition to my over-stuffed hobbyist's bench. Besides using it with my newly re-capped Tek 2445 scope, I intend to use the 650MHz Philips FET probe as a high impedance input buffer for my modest RF Explorer-3G Combo spectrum analyzer in certain applications.Regards