Restoration of an Eico 460 DC Wideband Oscilloscope.
Gopher, I am afraid I have bad news for you. But before you become seriously dejected, like everything else in life, there is some good news too.
First the bad. Your EICO is barely a 'scope.
In the great universe of test gear, you have Bentleys and Rolls Royces. You also have (had) Yugos. Your EICO is a Yugo. EICO was a very low budget maker of inexpensive test equipment in the 1950's and 60's. They made several different pieces, vacuum tube volt meters, tube testers, capacitor checkers, and oscilloscopes. Much, if not most, of the stuff they produced was in kit form.
You bought a kit, bought a soldering iron, hopefully read the instructions, and blobbed everything together with solder. If everything went according to Hoyle, you had a VTVM, cap. Checker, or whatever that worked after a fashion. I would posit that literally hundreds of thousands of EICO kits were made and sold. Every great once and awhile, an unbuilt kit will show up on Ebay. Unfortunately, these devices were not really precision equipment. If you were very careful and diligent, you ended up with something that was at best, serviceable.
The way EICO made their money, was by supplying the would-be electronics tech with something that had the lowest priced components available. Your 'scope has numerous deficiencies designed into it to keep costs low. One, and you have now found this out, was that they didn't use a probe per se. You can craft a probe from VTVM probe bodies, and as been suggested, make or secure a demodulator probe, but many folks in the day just used a hank of wire. Another issue with 'scopes like an EICO, is that they had a VERY limited bandwidth. Meaning that the frequency range of the instrument was quite narrow. The 460 was touted as a Wide-Band oscilloscope.
I don't know the specs. For the 460, but I suspect it isn't much more that a few hundred kHz. This narrow bandwidth allows you to only work with frequencies in the audio range and a bit better. The standard 'scope most hobbyists use on old radios is at least 10 MHz, and preferably 20 to 50 MHz.
Lastly, none of EICO's equipment was 'calibrated'. Meaning that you could not accurately measure a signal for amplitude and frequency (well, you sorta could, but with difficulty). My vintage Tektronix 564B on the bench can, along with about a dozen other makes and models of lab grade gear. EICO, along with RCA, Heathkit, and a pile of other makers usually only produced service grade equipment. With calibrated 'scopes, you pull up a waveform on the CRT, read how many divisions in amplitude (vertical), and time (horizontal) the signal is, and multiply those numbers by the dial settings.
Can't do that with service grade stuff. In a word, your EICO is barely an oscilloscope. Now that I have thoroughly trashed your recent acquisition, let me tell you the good news. That 'scope can be a great learning tool, and a lot of fun. Buried deep on a shelf in my basement, is an old EICO 425 'scope.
Have had it for decades, and don't intend to get rid of it. I derived a lot of enjoyment messing with the thing, and learned a tremendous amount about how 'scopes work playing with it. If I had never played with it, or the vintage Clough-Brengle 'scopes I have, which weren't a whole lot better, my understanding of the Tektronix 'scopes I own would have been much harder to come.
I suggest you cobble up a few probes. A ground lead, a straight red probe, and a demodulating probe. Go through the manual for that EICO and study it. Figure out how it works, and then use it. Once you have spent some quality time with it, and really understand how it operates, you will move on to some better grade of instrument.
![Flywheel Flywheel](http://i.imgur.com/0119SzV.jpg)
It is time that won't be wasted. J.D. Leach Ploughing my Jingle into Clough-Brengle. Eico sold the kit probes separately. Schematics here All that has been said about the Eico 460 is correct. It is an old recurrent sweep scope that mostly sits unused in my garage because of the 4 channel 150 MHz Tektronics 2445 in my shop space.
![Eico Oscilloscope Model 460 Manual Flywheel Eico Oscilloscope Model 460 Manual Flywheel](/uploads/1/2/5/4/125422863/925012631.jpg)
All that said, when the radios up until about 1960 or so call for scope for alignment of FM, scopes like the 460 is what they had in mind. Viewing what is coming from a demod probe or the action of a ratio detector or discriminator is not all that demanding of a scope. The 460 had enough bandwidth to show the 3.58 MHz color burst in some fashion for early color TV. You CAN service an early TV with one. That is how they were used.
With respect to modern scope specs the old EICO 460 is 'barely a scope' but was not so bad in its time when compared to similar 'service scopes' in kit form, and much better than most Heathkits and even some factory assembled commercial units. Actually it was a great success for EICO and tens of thousands were sold, this is why the 460 is still fairly common today. Vertical amp bandwidth is not so restricted with a very respectable 4.5 MHz (at -3 dB) which is more than you'll ever need for servicing old radios, audio and TV sets (including color), and is DC coupled (goes down to 0 Hz) which was a rare feature in cheap scope kits.
It's surely not a TEK but is still usable for basic troubleshooting work where you mostly need qualitative (and not quantitative) indications. Without an attenuator probe it can handle a 600 volts (DC + peak) signal and you don't incur the risk of damaging (impossible to find) dual FET transistors in the input amp of your modern TEK scope if your probe ever slips and touch high voltage parts in the set you're troubleshooting, being a tube based circuit it's allmost foolproof.
It has only basic controls and is very easy to use. The probes were sold separately by EICO but could be easily duplicated (schematics are available).
Of course, being a 50+ years old scope you'll need to replace many drifted value resistors and leaky coupling caps to make it stable and reliable, but this is part of the fun (?). Though not a stellar high-tech laboratory scope the 460 has a great educational value and (once restored) is still useful for basic service work. Instead of trashing the venerable old 460 some respect is due to the engineer who designed the circuit and attained fairly respectable specs with so few parts and tubes.