Tektronix 214 Storage Scope


ditter2
 

There is a safety issue with modifying these 200 series analog scopes with either external batteries/power supplies, or installing BNC connectors to allow use with other standard scope probes. These scopes are double insulated. So adding a BNC connector with exposed “ground” or external batteries can expose the operator to the elevated voltage the scope is floating on, with risk of electrical shock.
As Dennis replied, there have been several postings on alternatives for the single ‘A’ size NiCd cells in the original battery packs. A simple no fuss mod is to replace with nickel metal hydride cells. Some searching on the Internet will come up with vendors selling the odd single 'A' size cell Tek used in these scopes. You can substitute without changing the charging circuit, however it will take a long time to fully charge with the lower charging current the NiCd cells could handle. But on the upside, the run time is considerably longer as the Ni metal hydride cells have nearly 10x the mA/hour rating of the original NiCd cells. A bit more work is required to update the charging circuit for faster charging. A good design will incorporate a “smart” charging IC, to prevent overcharging, as well as disconnect the battery from the load when the voltage gets too low – the cause of dry cell leakage.

Steve


 

Hi Carl,
I found one for sale at a swap meet that didn't work so I was able to get it at a bargain.
Thanks to a friend I discovered a custom made battery pack was readily available for less than $20.
With a new battery pack I was amazed that this little scope ran for over 6 hours on a full charge.
It is an extremely handy scope to have when you are working on equipment where there is 220V or 440V AC power or isolated equipment where it would be dangerous to connect a conventional scope up for fear of a ground loop blowing out the scope.

I love my 214 storage scope. A few years ago I even found the carrying case for it.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Carl Hallberg via groups.io
Sent: Friday, January 15, 2021 9:28 AM
To: TekScopes@groups.io
Subject: [TekScopes] Tektronix 214 Storage Scope

Hi Group,
Some years ago I got 2 basket case scopes. The problems involved a leaky diode and bad trigger chip in one and for both I decided to remove the batteries, and not have them internal to the scope. They had been leaking and I didn't want anymore damage. The regulator is a shunt type because a series regulator would have a voltage loss across it. It is good to plug it into the cigar lighter of a car or use a gel cell battery, but no longer uses the internal charging. I sold one of them to Jon Batters, who I miss on Tekscopes. Talked to him on the phone couple of times. Good conversations. The 214 nice little scope but only 500KHz.

Carl Hallberg (W9CJH)

https://groups.io/g/TekScopes/album?id=259407









--
Dennis Tillman W7pF
TekScopes Moderator


Carl Hallberg
 

Hi Group,
Some years ago I got 2 basket case scopes.  The problems involved a leaky diode and bad trigger chip in one and for both I decided to remove the batteries, and not have them internal to the scope.  They had been leaking and I didn't want anymore damage.  The regulator is a shunt type because a series regulator would have a voltage loss across it.  It is good to plug it into the cigar lighter of a car or use a gel cell battery, but no longer uses the internal charging.  I sold one of them to Jon Batters, who I miss on Tekscopes.  Talked to him on the phone couple of times.  Good conversations.  The 214 nice little scope but only 500KHz.

Carl Hallberg (W9CJH)

https://groups.io/g/TekScopes/album?id=259407