Re: Tektronix Cables Found


I learned an interesting lesson about eBay pricing trends from the CT-1 and CT-2. Back in the first half of the new decade (approximately 2000 to 2005) the CT-1 and CT-2 sold on eBay for $25 to $35 typically. I bought a few in those years and I kept track of the prices for them in case I wanted to buy one or two more.

Economists study auctions to gain an understanding about how prices are set for goods and services. There are few constraints on prices in an auction so whenever an auction for an item is successful it matches a seller who is willing to sell an item to a buyer willing to buy it for a price they both perceive to be fair. Auctions continuously establish the fair price for an item even as people's perceptions continuously change due to surrounding conditions. Most people alive today are forced to deal with a totally different system of pricing where items have fixed prices (and price stickers to reinforce this concept) and your only choice is to take it or leave it at that price. As recently as 150 years ago in the US there were no fixed prices and everything was negotiable in the form of barter which is just a variation on an auction.

eBay brought back our ability to barter for items we wanted as was done in the 1800s. One day I saw someone list a CT-1 for a starting price of $125. I send him an email telling him he should take a look at the current prices and the completed listings to realize he overpriced his listing and he would never sell it at that price. As politely as he could he told me to piss off.

He kept relisting his current probe every week and it never sold because there were always others listed for $25-$35. Most buyers knew there was almost nothing that can go wrong with these things so why pay more for one? This went on for at least 6 months then someone bought this sellers CT-1 current probe. This probably happened because that week there were no others listed and the buyer needed it in a hurry or didn't know how to look up the price of completed listings.

Overnight the new listings for these current probes all jumped to over $100 and stayed there. This seller had forced the asking price to jump almost 4X by what he did. After a while I stopped following the prices since I was not going to pay that for something I used to pay a lot less for. Prices for these things on eBay are now off the wall. $125 would be a bargain compared to what they are asking today.

Since then I have seen the same kind of thing happen with other items. But the opposite must happen as well from time to time when the market adjusts the price down to a level where buyers see the value of something and the demand starts to pick up. At the higher price there was no demand at all.

Dennis Tillman W7PF

-----Original Message-----
From: [] On Behalf Of Greg Muir via Groups.Io
Sent: Friday, August 16, 2019 10:28 PM


The offerings from distributors are poorly worded to a great extent making it rather confusing as to what the offering is.. Looking in a 1966 Tektronix catalog (yes, these things have been around for some time) on page 145 they single out the "probe" (cable) from the CT series current transformers by stating that the "probe" serves as an interconnecting cable between the current transformer and oscilloscope. And it was a jaw drop to see the prices then as compared to now:

CT-2 current transformer: $17
P6041 current probe: $12
Both together: $31

If you look on Newark, they specifically call out the P-6041 as the cable only ( and offer the CT probes together with the P-6041 for a price in the $800 range. The current price offering as compared to the 1966 one seems to have appreciated in a manner akin to that of gold.

As to why one would give a cable the label of "probe" as well as a probe model designation is beyond me. The CT-6 is a horse of a different color and also draws a hefty price close to $1k. But it's bandwidth is good to 2 GHz.


Dennis Tillman W7PF
TekScopes Moderator

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