An internet search returned more links and threads on the subject of a Progressive EMS hum than I cared to read. The few that I did all came to the same conclusion: the hum is from an aged or dirty contactor. I called and talked to Progressive's tech support and then submitted a claim form today, so obviously I'm waiting for a reply.
The purpose of this thread is to show the tool I used to objectively measure the hum before talking to the Progressive tech.
First though, a shout out to AlexPeterson who first mentioned the Spectroid app here: https://gdrvowners.com/forum/operati...260#post109260 It's a very useful app!
Below is a screenshot with just ambient noise in the trailer. All power is off. In PowerPoint I added the blue vertical and horizontal lines that cross at the point of interest (db level at 120hz).
This next screenshot is with the phone in the exact same location (near the internal EMS) but with external power applied. FYI, there was no difference in the hum with the Victron Multiplus I have installed in my trailer either on or off.
I was surprised the app identified the hum as 120hz -- I expected a 60hz measurement. Given the baseline of -99db and the measured -65 db, I think that means the hum is 34db? (I understand the basics of decibel measurements but make no claim to expertise.) Someone please correct me if that's wrong.
Regardless of the numbers, that hum is very noticeable and a nuisance.
I learned after taking the shots shown in this post that it is possible to zoom in using the "pinch" method. Apparently there's a lot more to learn about the app. For more about how to zoom, see https://www.youtube.com/watch?v=npUQj0nLw88 Using Spectroid to find The Hum by a content creator named Zalex.
I'll update this thread once the hum is resolved.
Howard
P.S. Yoda -- since the Spectroid app is free, I'm not sure you're allowed to get it.
The purpose of this thread is to show the tool I used to objectively measure the hum before talking to the Progressive tech.
First though, a shout out to AlexPeterson who first mentioned the Spectroid app here: https://gdrvowners.com/forum/operati...260#post109260 It's a very useful app!
Below is a screenshot with just ambient noise in the trailer. All power is off. In PowerPoint I added the blue vertical and horizontal lines that cross at the point of interest (db level at 120hz).
This next screenshot is with the phone in the exact same location (near the internal EMS) but with external power applied. FYI, there was no difference in the hum with the Victron Multiplus I have installed in my trailer either on or off.
I was surprised the app identified the hum as 120hz -- I expected a 60hz measurement. Given the baseline of -99db and the measured -65 db, I think that means the hum is 34db? (I understand the basics of decibel measurements but make no claim to expertise.) Someone please correct me if that's wrong.
Regardless of the numbers, that hum is very noticeable and a nuisance.
I learned after taking the shots shown in this post that it is possible to zoom in using the "pinch" method. Apparently there's a lot more to learn about the app. For more about how to zoom, see https://www.youtube.com/watch?v=npUQj0nLw88 Using Spectroid to find The Hum by a content creator named Zalex.
I'll update this thread once the hum is resolved.
Howard
P.S. Yoda -- since the Spectroid app is free, I'm not sure you're allowed to get it.
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