Bob:

I have done this, and it has reduced the hum to some degree.

But, the hum still gets slightly but noticeably louder when I transmit at
any power level.

I don't recall having this problem with other similarly rated power
supplies.

Do you think this is normal;  I just wasn't expecting it, I guess.

Tom Behler: KB8TYJ


-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Bob Tinney
Sent: Saturday, December 12, 2015 3:17 PM
To: [log in to unmask]
Subject: Re: Re-thinking New RS35 Power Supply Issue Again

Tom,

As others have said, the hum is probably coming from a vibration in the
steel cover.  When I had an Astron RS35, I stuck a folded file card between
the top edge of the front panel and the top cover and that really reduced
the transformer hum that I could hear.

Bob, K8LR, [log in to unmask]

On 12/12/2015 3:01 PM, Tom Behler wrote:
> Hello, again, everyone.
>
>   
>
> I am now beginning to wonder if today is my day for Murphy to make a 
> visit here, or just what exactly the deal is.
>
>   
>
> I was working a bit of the 10-meter contest today, and noticed a 
> further problem with the hum issue on my new Astron RS35 power supply.
>
>   
>
> I'm not sure why I didn't notice it last night when I did my testing, 
> but now, I find that whenever I transmit in CW at any power level-i.e. 
> 5 watts or 100 watts, the hum on the RS35 slightly increases.  In 
> other words, when I key down, I hear a slight, but noticeable increase 
> in the hum at any power level.
>
>   
>
> So, now, I'm trying to decide whether I actually should return the 
> supply to H R O.
>
>   
>
> I have my receipt and all other documentation, but I'm wondering 
> whether the folks at HRO would see this as a significant enough of a 
> problem for a product return.
>
>   
>
> The supply still seems to carry the load ok, and does put out what I 
> would expect in terms of output power readings, but the hum issue is a 
> noticeable one now, on several counts.
>
>   
>
> I don't mean to be obsessive about this, but I wouldn't expect to be 
> dealing with this sort of issue with a newly-purchased power supply like
this.
>
>   
>
> I'd continue to be interested in anyone's thoughts.
>
>   
>
> Tom Behler: KB8TYJ
>
>