Re: 184 Time Mark Gen. - 2nS & 5nS not working


Tom Gardner
 

Make sure you block any DC, and are very careful about the input power! If the DC block is a large capacitor (e.g. works to  kHz rather than MHz), consider whether any transients might be large.

Overkill? Possibly :)

On 08/04/20 03:17, Merchison Burke via groups.io wrote:
If you have a Spectrum Analyser, could that be used to check to 500 MHz output?


On 2020-04-07 9:22 a.m., david via groups.io wrote:
Thanks for the information guys, looks like I don't have the equipment or the knowledge to fix the 500MHz output. Not going to buy Nuvistors if I won't be able to check the results. My 465 is a 100MHz scope, it  shows 130mVpp signal at 200MHz output, so I believe that signal is OK. This 184 is working correctly except for the 500MHz. Only other issue is the 10MHz oscillator frequency does not have enough adjustment range. It is close enough, checking it with a GPSDO at 10MHz it is 9.999xxx, but it is at the limit of adjustment on C11. Any idea why the oscillator is beyond the range of C11 adjustment? Is it just the age of the crystal? Has anyone tried to reduce value of capacitor C11 by putting another cap in series with it? Only need to lower value of C11 a couple pF to fix it. I am amazed at how accurate this 184 is being all analog.
David


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