Re: [softrock40] I-Q signal levels of SR v6.3?
- On 24/10/09 20:45, Dave - WB6DHW wrote:
>The on air signal was around 59+20 dB which is ~0.5mV at the antenna -
> Sid Boyce wrote:
>> On 24/10/09 03:51, aa9wqham@... <mailto:aa9wqham%40aol.com> wrote:
>>> Either side should be fine. The voltage might be lower on the other side
>>> of the resistors because of loading from the sound card but won't make
>>> any difference measuring phase difference.Tthat won't change on either
>>> side of the resistor.
>>> Larry W9AMR
>> Only problem with Alex's BPF installed, I can't get to the resistors and
>> at the outputs there is 0V deflection at 0.1V/div both on RX and TX out
>> of the rig, except on TX I don't get any RF out - suspect a software
>> problem there as it used to work and I can back off the changes.
>> 73 ... Sid.
>>> In a message dated 10/23/2009 10:37:15 P.M. Eastern Daylight Time,
>>> sboyce@... <mailto:sboyce%40blueyonder.co.uk> writes:
>>> I have been looking at I-Q signals at "AUDIO OUT" on the scope with
>>> thumping great signals coming in, but I see 0V on my scope set at
>>> .01V/div and as slow as 0.5 sec. sweep speed. Scope is HP 1725A with HP
>>> 1Mohm 10:1 probes.
>>> I was hoping to measure the I-Q phase difference, same on TX.
>>> Should the measurements be made at the LT6231CS8 outputs ahead of the
>>> 100 ohm resistors R55 and R56?
>>> 73 ... Sid.
> How much RF are you putting into the antenna input. Unless you're
> putting a strong signal in, your I/Q output will be microvolts, or at
> most a few millivolts.
> Dave - WB6DHW
> <http://wb6dhw.com <http://wb6dhw.com>>
then I thought the LT6231CS8 gain would achieve a measurable signal on
73 ... Sid.
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
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