[Amps] FCC Denies Expert Linears' Request for Waiver of 15 dB Rule

[Jim Brown]

On Tue,1/3/2017 7:23 AM, Manfred Mornhinweg wrote:
> Bill,
>
> I have experienced several such cases of fellow hams blowing crud all 
> over a band, and "not hearing" those who report the problem. But most 
> of the offenders I have heard are operating factory-made equipment! 
> Very often they use a 100W radio to drive an amp that needs 50W or 
> less of drive, and don't connect the ALC line. 

USING ALC to control drive level for a power amplifier is a CAUSE of 
splatter and clicks. ALC should NEVER be used to set drive level. The 
ONLY good reason for using ALC between rig and power amp is to protect 
solid state output stages from damage due to a fault in the antenna system.

> Radios with slow-acting ALC are also famous for causing IMD blasts and 
> key clicks without even needing an amp, and there are many. But the 
> most usual way of producing lousy signals is by intentionally 
> defeating the ALC of the transceivers. In my environment they call it 
> "liberating" the radio, because the poor radio was tied down to just 
> 100W by the evil manufacturer, and by defeating that "brake" it can 
> produce 150W or so, when turning the mic gain to full and then 
> screaming into the mike, right?

I can't imagine what you are talking about. Since the days of separate 
TX and RX, I don't remember ever seeing a rig that didn't allow 
adjustment of output power.

> Sometimes radios develop faults that make the transmission dirty. I 
> remember a case of one station running a factory-made radio with a bad 
> PLL. It had an extremely high phase noise, and would transmit 
> modulated noise over a wide part of the band. That guy did reply to my 
> report, and told me that he had the same very high noise on RX, so he 
> thought that I was hearing what he thought was his local noise floor! 
> I tried to explain to him that probably his radio was faulty, and I 
> went on to explain about phase noise in frequency synthesizers and how 
> that can affect both TX and RX, but he totally rejected my suggestion 
> that his radio was faulty. He replied that his radio was putting out 
> "the full 100 watts and some more", and thus couldn't possibly be 
> faulty...

The error in this paragraph is that the radio "developed" a fault. Many 
rigs are DESIGNED with massive phase noise and nasty clicks.

73, Jim K9YC