VK2RK
Active member
I am very annoyed at been misquoted or even stating that I had said something I had not.
In the News letter the editor took the liberty to comment on a technical article I had submitted, there was no consultation as to the content of the comments.
What the comments state
“Robert said that the output of transmitters dropped by 10% if the voltage to them dropped this amount.”
I never said this, what I said is that the input power in my test case dropped by 10Watts
as far as the 81% not sure how this was derived and makes no sense.
“. Hence this conditioner is even more important for older rigs”
Old or New is not an issue, I2R losses are.
“Robert’s design is a belts and braces design and if you don’t require some facilities, it can be slightly simplified.”
There is no need to simplify anything, the design is the result of a lot of thought
Every time I submitted an article it created arguments, so this is the last time
Some extra thoughts on Robert’s DC conditioner.
Robert said that the output of transmitters dropped by 10% if the voltage to them dropped this amount.
This may be true of some later rigs, but older rigs on12 VDC however will not just drop 10% in output power with a drop in voltage drop of 10% in fact they will drop to around 81% of output due to the inverse power law. Some drop even more. Hence this conditioner is even more important for older rigs.
AC operated rigs also have the same problems and many USA rigs designed for 115 volt and 230 volts (sometimes switchable), the mains voltage on 115 volts was found to sag too much for proper operation on this voltage.
They recommended that the transmitters be run on 230 volts. Most USA premises had or have a centre tapped 230-volt supply and it is intended that light duty items work off 115 volts (centre tap to one end of the winding) whilst heavy current drain items ran across the whole winding.
Robert’s design is a belts and braces design and if you don’t require some facilities, it can be slightly simplified. Keep in mind with a 13.8-volt supply that R1 will dissipate around 76 watts at turn on with a current drain from the supply of 5.5 amps.
This power dissipation will drop fairly quickly as the 16.6 Farad capacitor charges. The resistor(s) can be overloaded for a short period but Robert suggests that four 10-watt ceramic resistors will survive this treatment as it is not as if 76 watts is being dissipated for long or often. The decision will be yours. I’d give it a go at that.
Rodney (Editor)
In the News letter the editor took the liberty to comment on a technical article I had submitted, there was no consultation as to the content of the comments.
What the comments state
“Robert said that the output of transmitters dropped by 10% if the voltage to them dropped this amount.”
I never said this, what I said is that the input power in my test case dropped by 10Watts
as far as the 81% not sure how this was derived and makes no sense.
“. Hence this conditioner is even more important for older rigs”
Old or New is not an issue, I2R losses are.
“Robert’s design is a belts and braces design and if you don’t require some facilities, it can be slightly simplified.”
There is no need to simplify anything, the design is the result of a lot of thought
Every time I submitted an article it created arguments, so this is the last time
Some extra thoughts on Robert’s DC conditioner.
Robert said that the output of transmitters dropped by 10% if the voltage to them dropped this amount.
This may be true of some later rigs, but older rigs on12 VDC however will not just drop 10% in output power with a drop in voltage drop of 10% in fact they will drop to around 81% of output due to the inverse power law. Some drop even more. Hence this conditioner is even more important for older rigs.
AC operated rigs also have the same problems and many USA rigs designed for 115 volt and 230 volts (sometimes switchable), the mains voltage on 115 volts was found to sag too much for proper operation on this voltage.
They recommended that the transmitters be run on 230 volts. Most USA premises had or have a centre tapped 230-volt supply and it is intended that light duty items work off 115 volts (centre tap to one end of the winding) whilst heavy current drain items ran across the whole winding.
Robert’s design is a belts and braces design and if you don’t require some facilities, it can be slightly simplified. Keep in mind with a 13.8-volt supply that R1 will dissipate around 76 watts at turn on with a current drain from the supply of 5.5 amps.
This power dissipation will drop fairly quickly as the 16.6 Farad capacitor charges. The resistor(s) can be overloaded for a short period but Robert suggests that four 10-watt ceramic resistors will survive this treatment as it is not as if 76 watts is being dissipated for long or often. The decision will be yours. I’d give it a go at that.
Rodney (Editor)
Last edited: