I hope your coming wattmeter will come properly set with reliable readings at least for CW keydown or average SSB power. It seems there are many cases they sell stuff non properly set. When I got the licence I too had bought a new swr-power which was showing misleading values. Luckily enough at the local ham radio club my elmers not only found the problem but in few minutes set it right (three trimmers....). I have to say my wattmeter was neither Chinese nor Indian (!!!!) but made in Japan... A reliable and cheap way to measure the power (not the swr) on CW keydown is the RF detector as the one sold by Hendricks.
Il 02/nov/2018 03:11, "Joe Puma" <
kd2nfc@...> ha scritto:
Ok? got it.
> On Nov 1, 2018, at 4:10 PM, Clark Martin <kk6isp@...> wrote:
>
> I should have said you need to subtract the Tx idle current instead of the Rx idle current.
>
> Sent from an iPhone, don't ask whose.
>
>> On Nov 1, 2018, at 12:13 PM, Clark Martin <kk6isp@...> wrote:
>>
>> You also need to subtract the Tx idle current.? You can find this by keying up the mic with no audio input.? This current is mainly the bias current in the finals but also the relays and some other things.? The Tx idle current will vary with band.
>>
>>
>>> On Nov 1, 2018, at 11:07 AM, Joe Puma <kd2nfc@...> wrote:
>>>
>>> Hey guys,
>>>
>>> I will probably have a watt meter in the coming weeks but I still haven¡¯t measured my power out on the uBitx. So with a dummy load hooked up I took some power measurements with my DMM. I am not sure if this is a good way to tell power output but here are some measurements.
>>>
>>>
>>> Voltage is 12.67 Radio idle and 12.45 while Tx¡¯ing. not sure which one matters most when calculating power or if the difference is negligible but I calculated wattage from the 12.45v
>>>
>>> band? ? ? ? current? ? ? ? watts
>>> 80? ? ? ? ? ? 2.18? ? ? ? ? ? 27.14
>>> 60? ? ? ? ? ? 1.50? ? ? ? ? ? 18.67
>>> 40? ? ? ? ? ? 1.97? ? ? ? ? ? 24.52
>>> 30? ? ? ? ? ? 1.42? ? ? ? ? ? 17.67
>>> 20? ? ? ? ? ? 1.65? ? ? ? ? ? 20.54
>>> 17? ? ? ? ? ? 1.22? ? ? ? ? ? 15.18
>>> 15? ? ? ? ? ? 1.15? ? ? ? ? ? 14.31
>>> 10? ? ? ? ? ? 1.0? ? ? ? ? ? 12.45
>>>
>>> If I take into consideration the .33a for radio idle (4w) is my RF wattage 4w less then my measurements.
>>
>> Clark Martin
>> KK6ISP
>> Another Designated Engineer on the Information Super Railway.
>>
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