Ifr-1500 New Clicking Sound...

[n2len]

Hello Everyone,
I am hoping someone can shed some light of a problem I am now having with my IFR-1500.
I was tuning a set of UHF cavities and when I first entered the 440 frequency into the service monitor I began hearing a quick clicking sound emitting from the right hand side of the unit. It seems as though when I enter a VHF frequency into the monitor is stops the clicking.

Any ideas of what this is?
Here is a quick video clip of the problem.

https://youtu.be/o_lpa1ibxw4

[jry]

IIRC that may be normal depending on the settings. Believe the speaker is on the right side which is probably where the sound is coming from..

Believe what is normally heard is the RX unsquelching as the tracking gen sweeps by.

Couldn't really hear the clicking in the video.

One clue may be to just turn the squelch up all the way.

The only relays are buried in the IF module for attenuation selection and maybe back in the power termination module ...not very many and very quiet in either case.

[n2len]

Thanks for the reply. It is pretty strange that the clicking noise appears on UHF. It is also seen of the crt monitor. When I switch to VHF it disappears.
I did read somewhere about reseating boards and chips, but I can seem to find that post.

Second issue....
I also want to mention that also when using the Alpha display the display is dim. The display works fine when using the scope portion.
I don't know if there is a part of the inverter board that works only for the Alpha display. Maybe failing capacitors.

[jry]

Not sure what you mean by seen on the CRT. The video is very brief.

There are alignments for the high loop and tracking gen ...the tracking gen and spectrum analyzer shouldn't really care about which band since they operate on the IF frequencies but it may not hurt to go through the full alignment and calibration anyway ( the 1500 is a PITA to fully calibrate ).

There is a separate adjustment on the CRT board for the digital intensity but it may not help much. Usually end up turning this up to the max.

The CRT used in the 1500 was primarily for analog scope displays ( same as the 1200 Series ) and when used in digital mode not really enough brightness to illuminate the entire screen except when maybe the tube was brand new. Bad design really and in the 1200 they went to a mix of VFD and CRT for digital and analog.

The later 1600 display module was much better for mixed analog and digital information and actually an OEM module.

[n2len]

That's very interesting to hear and I appreciate your reply and input! Let me make another video, I don't think the display will show clearly in the clip due to the FPS but I will try.
The display is quite lower than normal when using the menus and digital settings. Scope setting is fine.
But the clicking or should I say fluttering or timing comes and goes. More on UHF than VHF and located on the right hand side of the monitor.

Regards
Len