how much the two cables of the two lines must be in total
MY QO100 SETUP
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Hi it seems that you have not understand what to do. I will try to explain. The lenghts of the semirigits is not critical but you have to use as small as you can. Using a nail you have to remove shield from each of semirigit creating a window of 30 mm * 2 mm. When you remove the shield you must not remove the teflon dielectric. The two windows must be as same as possible. Then you put the two windows face to face in order to be possible to be coupled. You then fixed this using solder taking care not to put solder on the windows and reduce coupling.
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thank you for your patience, now I understand even looking at the picture window of 30 mm * 2 mm
73 de iw5bsf Roberto
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iw5bsf: https://www.ebay.com/itm/Acces…2500MHz-200W/123863443543
A few mouse clicks, pay ca. 6 euro ... and you're done !
Remember, after UHF-Unterlage (80's - 90's) one hour costs >50 euro! (also for hobby ; -)
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Hi, to use the AD8302 he need two same. He has already one similar.
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SV1BDS B.t.w. I received the CETC CTI OSC5A2B02 10 MHz OCXO today. Will take a little time to test it because I have too much projects to finish (like doubling the shelf surface with MDF in my shoe cabinet ; -)
Hi Remco,
OCXO arrived today. Did you use it ?
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I use the same used OCXO with very good results. A simple 5V regulator and a potentiometer for the fine tuning is ok for the first test to check if the device is working at all.
To make full use of the OCXO capabilities you need to design the powersupply very carefully, to get high stability.
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Hi TNX for info regarding OCXO.
A few days ago I read the Tx output as transmitted using a directional coupler and the Rx cable to the analyzer at the shack. I read what I transmit without power at output. For compare when I transmit I send -5 dBm. The spurious was -22 dBm so 17 dB down : very bad !!! The reason was a 402 MHz Lo and the incoming 2.3-2.5 GHz signals that come in the 430 MHz input of the up convert mixer. Two steps are made: A new mixer totaly shielded improve the signals by 10 dB and a second 430 MHz filter at the roof was added. The result is 55 dB down spurious !!!
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Hi, updated block diagram.
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Hi my new feeder.
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Hi, testing QO100 with SSB 30 mW at 1 m dish. I use the 20 dB directional coupler to reduce power from 3W to 30 mW.
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Hello George I finished assembling the directional coupler and enough + 10 dbm to test it which power is adequate?
73 de iw5bsf Roberto
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Hi Roberto, the AD8302 arrived ? Can you measure coupling and directivity of the directional coupler ? Your analyzer have tracking at 2.4 GHz ? What attenuators you have? Can you post a photo of your construction?
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Hello George the ad8302 has arrived today, I have an analyzer but without tracking for the attenuators I have two 8db or 10db (2x5) mini-circuits as a signal source a maximum level generator +10 dbm
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Hi Roberto, you have to solder coupling not only at the edges but all over the two cables without the solder goes to the window. Do you have two 8dB and two 5 dB attenuator ? Also what is the minimum level of your generator ? Do you have any terminators/dummy load for 2.4 GHz?
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hello George
Hi, ok I have two 10 db attenuators composed of 5 + 5
minimum level -100 dbm of the generator 10 db steps terminators/dummy 50 hom sma max 1watt dc-18 ghz
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Hi Roberto, you have to measure the coupling and directivity of your directional coupler. If you can find instructions on the Internet it's OK, else tell me to try to give instructions.
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Hi George thank support ok instructions Internet I'll let you know as soon as possible
73 de iw5bsf Roberto
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I found these notes i5tdj Piero sk
measure of derittivity
a source rf is connected to the input of the coupler at the desired frequency and to the output a load 50 hom that has very low ros (at least 30 db reyurn loss). From the secondary line will come out a saw proportional to the power going from the input to the load (since the load is very good, the power reflected, from the load to the input is negligible). This level is measured. The coupler is reversed, connecting the RF source and the load input to its output. low of the previous one. The relationship between the two signals expressed in db and the derittivity of the coupler
have a 436a power meter with a head of a minimum of -30 dbm + 20 dbm