EICO 369 Purchase

[Chris K]

After buying 2 electromechanical Knight sweep generators I could not get working, I bought an EICO 369 on eBay for alignments on older TVs using frequencies in the 25 Mhz range. Has anyone used one of these? I have the manual that has around 5 pages of service bulletins suggesting significant changes in capacitor and resistor values, lead length etc... Has anyone done these changes and did it significantly improve performance?

[Chris K]

Simpler question…shouldn’t I be able to take the RF output signal off the generator and see/confirm it on my scope? When I do this I get a waveform but it’s jumpy and my scope can’t give me a steady frequency readout. Am I doing something wrong? I’m not trying to sweep or anything else. I just want to check the output frequency and I can’t. I had the same issue with my Knight sweep generator. That makes me think I’m not doing something right

[Electronic M]

What is the max frequency of your scope and what frequency are you trying to see. If you've got a 5MHz scope and a 21MHz minimum generator the scope isn't going to be able to measure it's frequency full stop.

A digital scope's frequency counter isn't going to be able measure a swept frequency either as it expects a constant frequency. The markers on a sweep generator or the output of a generator designed for AM radio if within the frequency range of a scope should be measurable however if it has significant harmonic content that makes the output non-sinusoidal it will effect (confuse) the frequency counter and while manual measurement is possible it can be confusing.

This may sound wacky but on my non-swept tube generators anything adjustible under 30MHz I set the desired frequency on my Sony ICF-7600GR shortwave reciever which covers 150KHz to 30MHz (it also does Japanese and US FM bands) and dial the generator until I hear the generator then I reduce generator output coupling till I barely hear it then tune the generator again...

[jr_tech]

In what way is the waveform “jumpy”... amplitude, frequency or position? Could you possibly post a short video?

What scope (make/model) are you using and how is it connected?

jr

[Chris K]

Originally Posted by Electronic M

What is the max frequency of your scope and what frequency are you trying to see. If you've got a 5MHz scope and a 21MHz minimum generator the scope isn't going to be able to measure it's frequency full stop.

A digital scope's frequency counter isn't going to be able measure a swept frequency either as it expects a constant frequency. The markers on a sweep generator or the output of a generator designed for AM radio if within the frequency range of a scope should be measurable however if it has significant harmonic content that makes the output non-sinusoidal it will effect (confuse) the frequency counter and while manual measurement is possible it can be confusing.

This may sound wacky but on my non-swept tube generators anything adjustible under 30MHz I set the desired frequency on my Sony ICF-7600GR shortwave reciever which covers 150KHz to 30MHz (it also does Japanese and US FM bands) and dial the generator until I hear the generator then I reduce generator output coupling till I barely hear it then tune the generator again...

Hi Tom...so this newfangled Fnirsi digital scope won't be able to help me align these TVs with this generator? I have a 60MHz Tektronix 2213A analog scope. Should it work on that? There are pictures online of individuals measuring the EICO 369 RF output (just the RF output...no sweeping or markers) with new scopes like Rigol equipment with perfect waveforms.

[Electronic M]

Originally Posted by Chris K

Hi Tom...so this newfangled Fnirsi digital scope won't be able to help me align these TVs with this generator? I have a 60MHz Tektronix 2213A analog scope. Should it work on that? There are pictures online of individuals measuring the EICO 369 RF output (just the RF output...no sweeping or markers) with new scopes like Rigol equipment with perfect waveforms.

I may have misunderstood what you were asking about doing...
I assumed above that you were using the scope to check/calibrate frequency output of the sweep generator....Which is a whole different can of worms than actual TV alignment using the scope and sweep generator.

Generally speaking you want to calibrate the fixed frequency markers (especially if they're not crystal derived/controlled) and not calibrate the sweep...So long as the sweep extends past the lowest and highest frequency markers and the sweep is flat (ignoring marker blips) when the generator output is bypassed directly to the demodulator probe it should be fine.

Some of the below may be slightly wonky compared to your setup as I'm only familiar with sweep alignment with the B&K 415...It basically packaged multiple alignment instruments and cables into one simple package and had an X-Y output any scope could use...You can achieve the same effect with other/older equipment but the connections are somewhat different.

You can use any of your scopes in X-Y mode for alignment (as long as they have X-Y mode and you have a demodulator probe or connect after the sets detector) with a sweep generator for alignment. The demodulated output of the sweep generator (which is close to DC) after going through the TV and a demodulator probe is fed into the X axis of the scope (the scopes Y axis has to be fed by the (often 60Hz) sweep oscillator. I think there were some applications for undemodulated sweep.

[Crist Rigott]

Yeah, I use a 369. It works well.

[Chris K]

I have the B&K 415 but it doesn't work for the lower frequency alignments. BTW, thanks Crist for the Briefcase couplates. Installed and working great!