|
Tom I opened up the L7 today and the 2.2 meg resistors 8 of them rather than reading 17.6 Megs are actually reading 16.66 Meg. or just less than 5% off. Not sure if that is the problem perhaps? R17 is the issue, R17 is 10K and adjustable any idea of where to get that little thing? If you think I'm wrong on the dropping resistors and the effect they would have on the proper voltage reading let me know please. Thanks 73 Tim WB8UHZ
On Wednesday, January 8, 2025 at 11:19:24 AM EST, amfone via groups.io <amfone20000@...> wrote:
Thank you Thomas yes these are carbon style resistors that Drake used back in the day and over time they age, take in moisture etc. and change in value I'm hoping that is the issue as I purchased new resistors from Mouser. Thank you Tim
On Wednesday, January 8, 2025 at 09:43:20 AM EST, Thomas W9TAB via groups.io <electron@...> wrote:
Tim,
Carbon composition resistors typically increase in value over time due to absorbing moisture.?
That is the reason the voltage divider network resistance has increased causing the voltage to read low.?
Military spec publications identified this a long time ago and Allen Bradley recommended taking the resistors and putting them in an oven at 150F for 5 days to return them to spec.?
Naturally in your case it makes more sense to just replace them if you cannot adjust it with the potentiometer, after all, that¡¯s why it¡¯s there. ?
On Jan 7, 2025, at 10:47?PM, amfone via groups.io <amfone20000@...> wrote:
|
