Hello friends, I’m glad to have your help.
We are aligning two PTPs that work in the 13GHz band, the radios are already installed in the local and remote tower, they are 2+0 radios, the TX and RX frequencies have already been configured and it is expected to reach a link with RX(-44 dBm), when choosing the MRMC Script Operational Mode (Fixed/Adaptive). Which of the two should be used to align 2 PTPs? fixed? or Adaptive? and when reaching the desired link level should be left in Fixed or Adaptive?
What other criteria do you recommend to achieve an optimal and fast link?
rough alignment using link planer install documents works very well and even gives you true and magnetic bearings. This will get you linked at least.
once linked, lower the tx power until the link drops, then raise it 3db to allow it to link, do this on both ends. make small fine adjustments and keep lowering the tx power until you can not gain back any signal stability with the lowest tx power settings you can achieve. this will ensure your link is as close to centered as possible and most definitely not on a side lobe.
If the link drops and does not come back after a 3db raise, your on a side lobe, leave tx power alone and adjust both ends until it links again.
this is a slow and frustrating task but patience and perseverance pays off as you increase your link budget and stability. the install doc from link planer will give you your targets to hit and you should be within 1 or 2dB with the stated SNR at the stated TX power levels, so once your done aligning, turn the power back up to what it says it should be.
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When installing a radio we must configure it according to Engineering (Link Planer / Budget) There for example puts the TX Level (power), Radio frequencies, Modulation.
When you say change the TX, what do you mean? for example for an X radio, we usually place TX at 26 and there we leave it until we achieve the link. How do you get the link by varying the TX? Thank you for your comment.
Initial config is to planned operations configuration. So you worked out in link planer that you need a TX of 26, set it to 26. You configure the radio to spec before you install it and make the rough alignment which comes from your compass and the install document.
Once the initial link has been established, then you start turning TX power down to perform fine adjustment alignment.
The whole goal is to align your link at the lowest TX power that can sustain a link. This makes sure that side lobes are minimized during alignment so that it is easier to find and center on the center lobe for signal.
So your link has a master and a slave, your aligning the slave side, turn the master radios tx power down from 26 to 23, if the link still stays up, turn down to 20 and continue until the link drops and does not come back up. Once you confirm lowest tx power to hold a link. Start aligning the slave starting usually with azimuth then elevation, repeat until your salve side RX power is as good as it can get. Then reduce the slave TX power like you did the master and then align the master to the slave. Repeat this until you are as close to the install document as you can get.
