Jim,
I checked with the RF voltmeter (good to VHF+).? Not sure how accurate it is, but ran my Measurments sig gen into it set to 50,000 uV out.? Voltmeter read 10mv at 58 MHz.? Sig gen set to 100K uV, read 40 mv.?? If the sig gen is still near cal, indicates the Rf voltmeter is reading low at these low levels.
Cross checked the sig gen into my log RF power meter...? 100K uV = -10 dbm (70 mv) & 50K uV = -15 dbm (40 mv).?? Sort of close...? The voltmeter diode detector may not be getting turned on well at these levels (?).? The log pwr meter is 50 ohms.? For a point of reference TP18 is reading -47dbm (1 mV) into a 50 ohm load; expect it is loading down the TP.? Wish I had high dollar test gear!? With that in mind, and not knowing how much the voltmeter probe loads the circuit, got these readings...
TP 12, Clk2 - 180 mV
TP 15, Clk1 - 180 mV
TP 18, Clk0 - 300 mV
Considering the voltmeter may be rather low, might translate to 400 mV, 400 mV, and 600 mV.? Don't know what the spec is, but seems on the low side.? Will try to measure with a friend's faster scope and report back.
Raj,
It does transmit OK, both in CW and SSB, but the pwr out is low. Now getting 1 watt on 40M, CW and 4 watts on 20M CW.? Cross checked the dummy load meter against my Elecraft K2.? It is indicating 10 watts from the K2, so should be pretty close.? RX RF sensitivity (and audio out level) are also both low.
Still trying to figure this out.?? Thanks for all the suggestions.
Woody,? KZ4AK
On 10/25/2018 14:16, Woody wrote:
Good point Jim.? It is rated within 3db at 35 MHz.?? Didn't expect an accurate reading at 45, but did expect to see something.? Will double check with my RF voltmeter...
Woody? -? KZ4AK
On 10/25/2018 5:07, jim via Groups.Io wrote:
Maybe a dumb question but its gotta be asked ...how fast is your scope?
Clk 0 is 12 Mhz or so
Clk 1 is 45 +/- 12 Mhz (33/57 Mhz)
Clk 2 is 45 Mhz to 75 Mhz
TP1 is directly off the antenna (think microvolts)
Jim
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