New DaveMade M80 fan noise on receive.

[snippits75]

Just got a new original DaveMadeNJ M80 amp 2x HG 2290. It looks top notch, and it talks top notch. Could not even get it hot with my loud mouth.

Have one problem with it. Fan noise on receive, and it's definitely the fan making a low hum in my receive. I can turn the volume all the way down on my Cobra 29 LTD with the amp off, and it there is no fan hum. Then flip the amp on, and hear the hum wind up to a steady low hum.

Talked to a local CB tech last night, and he said put a filter capacitor across the fan. Skip was so strong last night his transmit was getting wiped out, so I did not hear most of what he said to do.

Have not opened up the amp yet, but I do think it's 80mm fan measuring from the top side. It's a nine blade fan, so I am pretty sure it's not a bottom dollar fan. It's a little bit too loud for my ears, but I know how to fix that. Just need to know how to fix the fan noise on my receive. Thanks

 

[Tokin]

Just got a new original DaveMadeNJ M80 amp 2x HG 2290. It looks top notch, and it talks top notch. Could not even get it hot with my loud mouth.

Have one problem with it. Fan noise on receive, and it's definitely the fan making a low hum in my receive. I can turn the volume all the way down on my Cobra 29 LTD with the amp off, and it there is no fan hum. Then flip the amp on, and hear the hum wind up to a steady low hum.

Talked to a local CB tech last night, and he said put a filter capacitor across the fan. Skip was so strong last night his transmit was getting wiped out, so I did not hear most of what he said to do.

Have not opened up the amp yet, but I do think it's a either a 80 or 92mm fan measuring from the top side. It's a nine blade fan, so I am pretty sure it's not a bottom dollar fan. It's a little bit too loud for my ears, but I know how to fix that. Just need to know how to fix the fan noise on my receive. Thanks

If it were me id replace the fan with a quality EBM papst metal fan. I find them on ebunk often. Ill search EBM for the size, cfm and voltage I need then search ebay for the ones I need. I dont think ill ever buy another plastic unit.
https://www.ebmpapst.us/en/products/compact_fans/axial_compact_fans/axial_compact_fans.php

 

[Crusher]

I’m sure if you call up Chris, he will make it right.

 

[2NC995]

Snippets - can we see when you pull the cover off?

 

[snippits75]

Snippets - can we see when you pull the cover off?

Yes I will, but I might need to make a call, so I have not pulled the cover yet.

Pretty sure looking down through the holes where the fan is mounted the fan wires have some turns around a ferrite that does not block the air flow.

 

[snippits75]

I’m sure if you call up Chris, he will make it right.

I will call tomorrow, and leave a message!

 

[snippits75]

If it were me id replace the fan with a quality EBM papst metal fan. I find them on ebunk often. Ill search EBM for the size, cfm and voltage I need then search ebay for the ones I need. I dont think ill ever buy another plastic unit.
https://www.ebmpapst.us/en/products/compact_fans/axial_compact_fans/axial_compact_fans.php

If I do end up having to replace the fan, I will buy a Papst 8412NGL 80x25mm. They are quite fans with good air flow. Can't say if it will help with the fan motor noise or not.

 

[Tokin]

I put a pair of Papst 4600x fans on my 300a and I can talk a long time and it never gets warm. The chrome lid came from a parts 300a that had been poorly peened for taller tubes so I didnt mind cutting the holes for the fans. I still have the pristine original lid.

 

[snippits75]

Chris is sending me a new fan today!

 

[543_Dallas]

Good deal. Just my 2 cents but keep an eye on heatsink temp if you decide to slow the fan down or swap it for a quiet one.

 

[snippits75]

Good deal. Just my 2 cents but keep an eye on heatsink temp if you decide to slow the fan down or swap it for a quiet one.

Will do, and thanks for reminding me. Cooling is job one, but I don't want to listen to a mini tornado either. Fan speed in the 2,000 to 2,500 range would probably be best, and not annoy the heck out of me.

 

[543_Dallas]

Will do, and thanks for reminding me. Cooling is job one, but I don't want to listen to a mini tornado either. Fan speed in the 2,000 to 2,500 range would probably be best, and not annoy the heck out of me.

I hear that. My antenna coax comes in through the grage. My noisy amps stay out there and the radios are in a spare bedroom.

A guy was asking me how long of a jumper he should use between his radio and amp. I told him I use about 60 feet.

 

[snippits75]

Just to update this thread.

Chris did send me a new fan. Unfortunately, it was a 80mm x 80mm x 25mm. I did install it, but the fan blades were bound on some wound ferrite chokes that are sitting above the transformer. The fan that came with the amp was a 80mm x 80mm x 15mm.

Anyway, I ordered an ADDA 80x15mm AD0812LX-D70, and installed it. Noise on receive is gone, and this fan is lots quieter than the old bad one. It's moving enough air to keep it good and cool. My loud mouth can't get the amp hot running the variable at max.

Chris did reimburse me for the ADDA fan. Excellent communication via email during the whole process. Very happy with my baby driver. Will work great to drive a six or eight pill.

 

[2NC995]

Chris did reimburse me for the ADDA fan. Excellent communication via email during the whole process. Very happy with my baby driver.

I would never imagine a CB amp builder reimbursing for a 3D party parts purchase.

I’m impressed.

Id say you did REAL good, IMO.