Would you get image noise though ?
Posts by G4IUG
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Just a thought about aluminum.
In the 60's you had to use silver plated everything on 2M, at least that is what we were taught by the old boys and the RSGB VHF/UHF manual. I bought into this but eventually discovered it was mostly hearsay and at best only marginal under some circumstances.
So aluminum, just go for it !
Dave G4IUG Ex G8EAO
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I don't see the need to feed LNBs with 12V when only one polarisation is used. It can be reduced until the drop voltage of the regulator is reached.
Very true, however I don't get the virtue of low dissipation ?
Dave
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You are going to dissipate power whatever happens, but it's not significant ?
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I'm not sure what the issue is here ?
To drop the supply to the TXCO just use a resistor, nothing more.
Changing the feed is either luck or a test gear solution. I measured mine, but then I have a calibrated HP8970B.
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Remove the capacitors on pins 6 and 7 and inject via a capacitor into pin 7 i/p, check with a very good scope and 10:1 probe that your signal is coming out of the o/p pin 6.
The board runs of a 6V regulator so you may have to reduce the voltage to your TCXO. I did this with a simple resistor and 100n decoupling capacitor.
You do need of course good skills and experience in this.
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It is documented here :
LNB Wobble | A tale of two LNB's -
I really can't see how this will reduce phase noise unless it is expectation bias ?
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I believe the FT-100 is very deaf outside normal amateur radio frequencies. So yes it tunes but really may not be suitable.
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Um, didn't I already link to my own similar observations above ??
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Obviously it is the crystal or the oscillator built into the chip !!
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Wolf
This is not the wobble we are all talking about.
Dave
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No
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It isn't jumpy, have you got "first hand" experience of this particular issue ?
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I think we are talking about wobble not temperature affects ? The slow wobble occurs in a 21C temperature controlled lab over a a minute or two.
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The above was written 3 months ago and the 0.1ppm still looks good. The absolute accuracy is within specification and the temperature drift specification is way better. On any day, at any time, at any temperature, a SSB signal is perfectly on frequency. And no wires, splitters, boxes, antennas etc.
However doubts have been cast on GPS systems in general with poor phase noise.
I have the "HP 58503B GPS (option 0004) locked frequency standard" and had to disconnect it from my HP8566B low noise analyser, because although it made it very accurate on frequency, it ruined its performance. Go figure and YMMV ! -
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Hi Wolfgang
Thank you. I will go for that. It will take me a couple of weeks to get everything together.
Many thanks again
Dave
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Please have patience with me ! How many programs run ? Is it two ? Omnirig and SDR Console ? Do you pay for them ?
So far I have only used the software that came with SDRplay.
Many thanks Dave
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The 144 MHz Down-Link output of the Transverter goes in to a splitter and from the splitter one signal goes still to the IC-9700 (2m) and the other signal goes to the SDRPlay RSP2Pro.
I am confused over this. Does SDRplay look continuously over 144.500 to 144.800 (a little more though) and superimpose a marker from the transmit chain of the 9700 ?
I would be very, very interested if you could tell me how to do this, or point me in the right direction. I will be using a different Icom but with a CAT interface.
Thanks Dave