G0MJW fw_setenv ad936x_ext_refclk is for 250 MHz ?
With 0.32 it needs single quotes.
Posts by SV1BDS
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Hi,
I measure 17 dB SNR with -130 dBm input at this system. Is this a real measurement or is fake? Have any one measure LNB sensitivity?
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Hi,
SNR improved still without lens at feeder. There is interference between 10 MHz reference and switching power supply.
PLL used with internal reference here.
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Hi,
A non LNB Rx using a homebrew feeder, a small teflox coax, a surplus mixer and a surplus Lo at 10,345 GHz providing output IF at 144 MHz. A SNR of about 10 dB was archived. May be the IF output is small and need amplify.
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Hi,
Overlapping the plots are more easy to see available working frequencies. It seems that the new one is suitable for 2.4,5.9,10 GHz.
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Hi,
As the directional coupler which is build some years ago it is good only for 1.2-2.4 GHz I try to build one for 5.9 GHz. The window is about 10 mm long by 1 mm wide. A margin of about 20 dB is available for measuring SWR.
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Good morning George yesterday I remeasured the directional coupler 2.4 GHZ the only measures but with one hour of heating of the bolometer hp as the manual says good results 23 db of coupling and the directives 39 db what do you think
73 de iw5bsf Roberto
You have a difference of about 16 which is enought to measure SWR.
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Hi,
In order to measure drift of my Lars GPSDO compared to a Cesium reference I try the following setup: The two 10 MHz sources feed to an SBL1 mixer and IF output of this (DC capable output) feed to a 50 KHz LPF. The result is a very slow changing DC voltage of about +-200 mV. The voltage is change very slowly and it is impossible to measure time from 0 to 0. For example it take about 14 min for 0 to 0. Also the change is not at the same direction all the time. So I have to find a better aproach to measure such small frequency drifts. So I connected the AD8302 which measure phase difference. Its readings was in sync was the DC voltage output from the previous settup. The phase was changing slowly and worst change was about 1 degree per sec. Taking into accound that a circle has 360 degrees this leeds to think that the drift was about 2-3 mHz at 10 MHz. This looks like compatible with a previous measurment.
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It seems that it is not a ground loop problem. It seems that one device when it is closed make the Prologix stop working.When the device is power up then Prologix works again.
Prologix answer:'For reliable operation, all devices connected to the GPIB bus must be powered ON even if they are not in use.'
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Hi,
There are ground loops problems with Prologix Ethernet adapter. When connected ta a single device or alone there is no problem. But when multiple devices are connected via proper cabling the Ethernet stops to answer even to ping packets. The problem is not from the Ethernet connection. The problem is not always noticed. But when noticed even the ground connection of the GPIB cables is enought to make it stop working. Any advice is welcome ...
It seems that it is not a ground loop problem. It seems that one device when it is closed make the Prologix stop working.When the device is power up then Prologix works again.
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Hi,
Spectrum Surveillance Utility by John Miles, KE5FX worked via Internet. As it requires little BW its working fine remotely.
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Hi,
There are ground loops problems with Prologix Ethernet adapter. When connected ta a single device or alone there is no problem. But when multiple devices are connected via proper cabling the Ethernet stops to answer even to ping packets. The problem is not from the Ethernet connection. The problem is not always noticed. But when noticed even the ground connection of the GPIB cables is enought to make it stop working. Any advice is welcome ...
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Hi,
POTY from 7470.exe .
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Hi, Prologix arrived and working with John Miles, KE5FX software.
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Hi
Two dBm meters Link .
"RF MILIWATT METER
THIS PAGE CONTAINS TWO VERSIONS OF MY MW METER, THE PIC VERSION WITH AD8318 AND THE ARDUINO VERSION WITH AD8317"
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Hi, thanks for the answers. My plans are to write my own Python scripts. Also to use 7470.exe as plotter emulator. At this Link it has software that can be used. My thought about Ethernet is that it will be available from any PC local or remote. Applications ideas are phase noise, alan deviation, real time web spectrum monitor of HF-UHF.
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Hi,
I plan to buy a Prologix GPIB Ethernet adapter. Any suggestions ?
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iw5bsf I have done something similar. You are right about the values. The critical is the ground paths of the two 56 ohm resistors. If they have inductance to the ground the actual attenuation will be smaller. To avoid high power passing I replaced variable R with a fixed one. Also use metal film or carbon for all as the usual resistors are inductive. I have also the W1GHZ 2.4 GHz transverter and begin assemby it for simplex usage.
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iw5bsf Hi Roberto, I measure my directional coupler and it is suitable for 1.2 GHz and 2.4 GHz only. In 5GHz it has hi SWR. In 5&10 GHz there is no difference between coupling and directivity. I was blind and happy with my directional coupler ...
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Hi, it seems OK now ...
