I got a new oscilloscope! Eico 430

[smbaker]

Scope is connected to a function generator outputting a 60 Hz sine wave on both horizontal and vertical input. The horizontal gain seems a bit wonky -- what's pictured is actually maximum gain, the knob fully clockwise, and my lissajous pattern is less than one division. So I'm thinking maybe the horizontal amplifier needs some attention. Vertical gain is good, as is focus and brightness of the CRT.

Oh, and I can't find the trigger knob anywhere, so it's going to be interesting to figure out how the trigger works. Maybe it's fixed to trigger at zero crossing? It's going to be an interesting journey.

Anyone else have an interest in vintage test equipment?

[RJFreeman]

Nice! it looks like it is good condition 
You will find the manual here:
http://www.kevinchant.com/uploads/7/1/0/8/7108231/eico_model_430_oscilloscope.pdf

if you haven't already....

[dr.diesel]

Very cool, love vintage gear, nice simple compact unit.

[LightlyDoped]

I never had Eico test equipment, but my very first ham radio transmitter was an Eico 720 that came as a kit. It only worked on CW. I later added an Eico 730 AM modulator. I loved the warm glow of those tubes.

[med6753]

That's a recurrent sweep scope. There is no "Trigger". Set the sync to "INT" then use the sync control and frequency vernier to stabilize the waveform. 

[joeqsmith]

Nice!   I like the section on probes in the back of the manual.   

[smbaker]

You will find the manual here:
http://www.kevinchant.com/uploads/7/1/0/8/7108231/eico_model_430_oscilloscope.pdf

Thanks. I had one in djvu format (never heard of that until this week), but PDF will be more convenient.

I'll probably shoot a try-out & tear down video at some point.

I never had Eico test equipment, but my very first ham radio transmitter was an Eico 720 that came as a kit. It only worked on CW. I later added an Eico 730 AM modulator. I loved the warm glow of those tubes.

This is my second piece of Eico test equipment. The first was a 369 RF sweeper, which has turned out to be a really nifty piece of equipment. I'm hoping to pair it with this scope in XY mode to do some radio alignment. I've already aligned one radio using the 369 together with my BK precision analog scope, but this 430 is nice and compact in comparison, and much better fits the period.

[smbaker]

I fixed it!

I noticed that the horizontal gain was actually working better as the sweep frequency was increased, almost normal up around 100Khz. Looking at the schematic, there was C23, an electrolytic cap in the horizontal amplifier circuit path, and I figured if that cap had failed that perhaps be attenuating the low frequency horizontal sweeps. Replaced the cap, and that was indeed it!

I knew I'd figure it out eventually, but I didn't expect the fix to come this easily.

[Cubdriver]

Glad to hear it was a simple fix and that you got it working again.  That's a cool old piece of hardware.

-Pat

[starlight_tools]

Have this same model of scope, it appears to be NOS, but no probes came with it.

[Housedad]

Trigger? We don't need no stinking trigger!

Nice scope.  There's an old scope of similar vintage in good shape on craigslist local to me.  It is tempting..... 35 bucks.

[0culus]

It's interesting to read old application notes from the days before triggered sweep oscilloscopes existed. Lissajous patterns are really a novelty these days, but before oscilloscopes were calibrated instruments, they were a pretty powerful way to glean a lot of info from an otherwise (by our standards) quite limited instrument.