Question about old electronics components

[Ism]

I have a Whites TM600 built somewhere in the 1980's so the electronics are 30+yrs old.
I replaced the electrolytic caps, pots and a couple other questionable components on the main board. That seemed to improve the stability.
I plan to upgrade the main board with all new components that are as good or better than original.
I'm wondering if it is recommended to do a full rebuild of the antenna circuits as well (not counting the toroid coils).
That would entail a lot of work getting the antennas apart so I don't want to do it unless it will be beneficial.

Thanks,

[Chet]

Hi Ism, I have many years of refurbishing electronic equipment. The procedure that works well is "Inspect and Repair as Required". For example if the antenna coils are not damaged electronically do not rebuild or repair. The changing of the electrolytic capacitors is good practice since they do fail with age. Resistors and small ceramic capacitors hold up with age. Exception is resistors that have suffered from heat and are discolored should be considered for replacement.

Transistors and diodes are low failure items. Normally they are not replaced unless found to be defective through troubleshooting an operational problem. If you do replace any transistors be careful to remove without destroying them. Suitable substitutes or transistors with different characteristics may cause undesired effects. Many of the circuits required careful custom biasing to operate with the transistors available at the time of production. So if you do change some transistors replace them one at a time then test. If the test indicates a loss of performance then re-install the original. In rare occurrences the circuit may require some modifications of resistor values to accommodate a substitute transistor.

Otherwise cleaning and cosmetic touch-up to your satisfaction completes the job.

[Carl-NC]

I agree with Chet, replacing anything more than needs to be replaced won't improve anything, and you're more likely to mess something up and end up with a dead detector. I routinely get detectors from the 70's & 80's that work just fine.

[Ism]

I felt the same, but wasn't sure since my knowledge is very limited in these matters.
Thank you both for great advice.