On Tue, 2 Jun 2009 17:29:33 +0000 (UTC), jhallen@TheWorld.com (Joseph
H Allen) wrote:

>In article <CZcVl.51777$Xo1.33938@en-nntp-07.dc1.easynews.com>,
>Joel Koltner <zapwireDASHgroups@yahoo.com> wrote:
>
>>VPI stands for "Value Probe Initiative," and there was a bit of a =
running joke=20
>>about how much of that "value" was for the end-user vs. Tektronix. :-)
>
>Hmm.. this might be the problem: US Patent 4708661, Nov. 24 1987.  =
"Modified
>BNC Connector for Active Probe".  It looks like the TekProbe patent ran =
out.
>
>The new patent is: D566047 (Apr 2008).  Claim: "The ornamental design of=
 a
>plug for accessory-host interface, as shown and described."
>
>So there is no technical advantage, it's just an ornamental design which
>is patented that so nobody can copy it.  Nice.

Aha.  Snarketing.

In article <CZcVl.51777$Xo1.33938@en-nntp-07.dc1.easynews.com>,
Joel Koltner <zapwireDASHgroups@yahoo.com> wrote:

>VPI stands for "Value Probe Initiative," and there was a bit of a running joke 
>about how much of that "value" was for the end-user vs. Tektronix. :-)

Hmm.. this might be the problem: US Patent 4708661, Nov. 24 1987.  "Modified
BNC Connector for Active Probe".  It looks like the TekProbe patent ran out.

The new patent is: D566047 (Apr 2008).  Claim: "The ornamental design of a
plug for accessory-host interface, as shown and described."

So there is no technical advantage, it's just an ornamental design which
is patented that so nobody can copy it.  Nice.

-- 
/*  jhallen@world.std.com AB1GO */                        /* Joseph H. Allen */
int a[1817];main(z,p,q,r){for(p=80;q+p-80;p-=2*a[p])for(z=9;z--;)q=3&(r=time(0)
+r*57)/7,q=q?q-1?q-2?1-p%79?-1:0:p%79-77?1:0:p<1659?79:0:p>158?-79:0,q?!a[p+q*2
]?a[p+=a[p+=q]=q]=q:0:0;for(;q++-1817;)printf(q%79?"%c":"%c\n"," #"[!a[q-1]]);}

"Joseph H Allen" <jhallen@TheWorld.com> wrote in message 
news:h03ib3$k9p$1@pcls6.std.com...
> So does anyone understand the point of Tektronix's new TekVPI probe
> interface?

Possibly.  It was meant to be as flexible as TekConnect (in terms of being 
able to hook up voltage probes, current probes, etc. and having them all "just 
work" and allowing *bi-drectional* communication between the probe and the 
'scope) -- which is more flexible than what TekProbe II can do (but if you're 
just using "simple" probes you'll never see this...) -- while being 
inexpensive (mainly much cheapter than TekConnect, which is quite spendy given 
the need to support >4GHz... and as cheap or cheaper than TekProbe II).

VPI stands for "Value Probe Initiative," and there was a bit of a running joke 
about how much of that "value" was for the end-user vs. Tektronix. :-)

> TAP1500 vs. P6245... no difference in specs, but TAP1500 cost more.  P6245
> available used for very little money.

The lower-end digital scope market is quite competitive... so I expect that a 
lot of margin is now built into accessories with the core scope price cut to 
the bones.  The "average" sales price of a scope today is probably <$5k, 
whereas when TekProbe II came out it was >$10k... which would be even more in 
"today's" money.

---Joel

jhallen@TheWorld.com (Joseph H Allen) writes:

> So does anyone understand the point of Tektronix's new TekVPI probe
> interface?  It seems to me pure connector conspiracy:

That's what I assumed too.

> So lets see, now we have:
>
> TekProbe-II: long standing probes...
>
> TekVPI: 4 GHz probe interface, but pointlessly different from TekProbe-II. 
> $400 adaptors allow you to use TekProbe-II probes...
>
> TekConnect: different from above to exceed 4 GHz BNC limit...
>
> TAP1500 vs. P6245... no difference in specs, but TAP1500 cost more.  P6245
> available used for very little money.


The high-end scopes don't even come with probes. They offer a discount
scheme, e.g.  "2.5GHz for the price of 1GHz". But the 2.5GHz model does
not come with probes, which are $4000 each...

> The Agilent situations seems better.  Their "high precision" BNC connectors
> are used on all of their scopes so all probes are more or less compatible
> with all scopes.

Didn't know that, never used an Agilent.

> I traditionally prefer Tektronix, but their probe situation is starting to
> really bug me.

That "legacy" probe situation helped to stop me spending ~$10-20k.

-- 

John Devereux

So does anyone understand the point of Tektronix's new TekVPI probe
interface?  It seems to me pure connector conspiracy:

So lets see, now we have:

TekProbe-II: long standing probes...

TekVPI: 4 GHz probe interface, but pointlessly different from TekProbe-II. 
$400 adaptors allow you to use TekProbe-II probes...

TekConnect: different from above to exceed 4 GHz BNC limit...

TAP1500 vs. P6245... no difference in specs, but TAP1500 cost more.  P6245
available used for very little money.


The Agilent situations seems better.  Their "high precision" BNC connectors
are used on all of their scopes so all probes are more or less compatible
with all scopes.

I traditionally prefer Tektronix, but their probe situation is starting to
really bug me.

-- 
/*  jhallen@world.std.com AB1GO */                        /* Joseph H. Allen */
int a[1817];main(z,p,q,r){for(p=80;q+p-80;p-=2*a[p])for(z=9;z--;)q=3&(r=time(0)
+r*57)/7,q=q?q-1?q-2?1-p%79?-1:0:p%79-77?1:0:p<1659?79:0:p>158?-79:0,q?!a[p+q*2
]?a[p+=a[p+=q]=q]=q:0:0;for(;q++-1817;)printf(q%79?"%c":"%c\n"," #"[!a[q-1]]);}