Wittig W202 200 MHz Scope probes - Four for £15 in the UK !

[Fraser]

I just thought I would share details of some probes that I just purchased from MCS in the UK via ebay.

MCS are selling W202 15/200MHz 1X/10X scope probes made by Wittig Technologies for only £15 + £3 p&p for a set of four ! The offer looked too good to be true but I received them today and was impressed with the quality. They have two trimmers in the BNC connector 'cube' and a trimmer on the probe itself. They may not be up to Tektronix standards but they would suit most everyday tasks. They are cheap as chips but decent quality so fill yer boots  

Take a look here:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=120580739499&ssPageName=STRK:MEWNX:IT

or ebay.co.uk item no. 120580739499

MCS appear to have plenty in stock and I just bought another set as spares !

I have no connection with MCS and offer this purely as a heads-up and no responsibility is taken if you don't like the probes for any reason.

[Kiriakos-GR]

well the Bandwidth  x1 15Mhz , its a bit low as spec.

The 10 X 15Mhz  = 150 ... not 200Mhz.

Any way its out of my field those items..
Some one more expert it could possibly help more. 

[Fraser]

Hi Kiriakos,

My RP2200 probes that came with the Rogol 1052E are rated at 1X = 7MHz and 10X = 200MHz but the key differenece for me is the input capacitance. The Rigol has 1X = 20pF and 10x  = 5pF. The Wittig W202 has a stated spec of 1x = 46pF and 10x = 15pf so it is likley to load a tuned circuit or pull an oscillator more than the RP2200.

BUT for around £4.50 delivered they are great for general work and virtually disposable. I have paid more for just a BNC/BNC cable ! I have several low bandwidth scopes like the TTi SM630 (20MHz) and the UNI-Trend UT-81B that will work well with these little probes  

I still have a pair of Tektronix probes but it's good to have some cheaper ones around for odd jobs when I go walkabout. Oh and before anyone starts shouting at me over safety testing and rated voltage... I only use quality Fluke or Tektonix scope probes around the dangerous stuff  

[alm]

My RP2200 probes that came with the Rogol 1052E are rated at 1X = 7MHz and 10X = 200MHz but the key differenece for me is the input capacitance. The Rigol has 1X = 20pF and 10x  = 5pF.

I don't believe this spec for a Hi-Z probe. Expensive ($300-$400) Agilent/Tek 10x Hi-Z 500MHz probes have about 8-12pF input capacitance. Their 1x probes have about 40-100pF input capacitance.

Wittig W202 has a stated spec of 1x = 46pF and 10x = 15pf so it is likley to load a tuned circuit or pull an oscillator more than the RP2200.

Those numbers are more realistic, although the 1x number sounds pretty optimistic unless it's a really short cable. Note that there's a lot more to probe design than just these specs, like dielectric absorption of the capacitor, and all kinds of parasitics. Much harder to design than the transmission lines normally used at these frequencies. Even seemingly simple stuff like the cable or tip hybrid (9Mohm resistor, basically) is a real science above 20MHz or so. But for unimportant stuff with low output impedances and relatively low frequencies, the cheap stuff should suffice.

[Fraser]

Oooops, sorry, I must have been tired last night... I misread the RP2200 specs... it was the input capacitance tolerances that are +-20pF and +- 5pF, not the actual input capacitance itself, sorry.

The stated input capacitance specs or the RP2200 are actually as follows:

X1 = 100pF +- 20pF
X10= 17pf +- 5pF

Please bear in mind what ALM has already said regarding the claimed specs. The Wittig probes, at least on paper, are better specs than the RP2200's. How accurate the stated specs are is another matter and I would not be surprised if they are optimistic at this price point.

As a side note, Hameg appear to sell a very similar probe to the Wittig under the name HZ154. It is rated at 100Mhz but unlike the Wittig instructions, Hameg actually detail the purpose of the trimmers as: 1 for LF and 2 for RF. Hameg HZ154 Specs to be found here:
http://www.hameg.com/473.0.html?tx_hmdownloads_pi1%5Bproduct%5D=HZ154

[alm]

As a side note, Hameg appear to sell a very similar probe to the Wittig under the name HZ154.

The Wittig pictures looked familiar, it's probably some generic probe that's frequently re-badged, I believe I've seen it on eBay as cheap no-name probe 'like Agilent/Tektronix'. For cheap probes, I would prefer straight 10x instead of switchable, since the switch adds extra complexity, and it's an extra thing to go wrong. One of the cheap probes I've seen had a bum switch which capacitively coupled the signal, even in the GND position, and switching between 1x and 10x was touchy. Ironically, most of the cheap probes seem to be switchable, and most expensive ones are not.

I would probably trust Hameg over Wittig (do they even exist anymore?) or no-name brands, since they're R&S's budget brand.

One of the strange things is that the cheap passive probes are about the same size as was common thirty years ago, even though today's components are like five times smaller. Nothing like the Agilent miniature or Tek compact probes.

[FreeThinker]

As a side note, Hameg appear to sell a very similar probe to the Wittig under the name HZ154.

I would probably trust Hameg over Wittig (do they even exist anymore?) or no-name brands, since they're R&S's budget brand.

Quick google pulls up a product list with latest products dated 2008 so possibly No they may not exist now, could be the reason for the low price (NOS)?

[alm]

Quick google pulls up a product list with latest products dated 2008 so possibly No they may not exist now, could be the reason for the low price (NOS)?

I remember a Wittig DSO that some people are trying to improve. My understanding was that the software sucked, and they went bankrupt before they were able to fix this, but released the software. I thought this was before 2008. But some part of the company may have been taken over.

[FreeThinker]

This is the website http://www.welec.de/english/09_contact/contact_01_adresses.htm doesn't inspire confidence

[Fraser]

UPDATE

As at 19 March 2011 MCS(UK) have these probe sets in stock again and they are selling well. I purchased another two sets as they are virtually disposable at £15 for four and perform well in daily use. I use them on RF electronics and have not noticed any bad behaviour from these probes up to their rated frequency. Digital electronics may be more demanding so if you don't expect Tektronix or HP performance at this price point you should be happy with them  

http://cgi.ebay.co.uk/Set-4-200Mhz-wittig-W202-scope-probes-brand-new-/120691289053?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item1c19c2ebdd

I just purchased a Velleman HPS140 for casual undemanding use up to 5MHz and these probes work perfectly with it as well as with my higher spec Hameg and Tektronic scopes.

[deephaven]

Thanks for the tip-off. I've just ordered a pack for my home lab.