Thanks for the reply.
So if I can’t increase the TX POWER, I need use other antenna with more DBI?
The distance is 64km and I’ve 2 tower (cancun tower 80mts High - Playa tower 60mts high)
ofcourse, much bigger antenna is an obligation. 64km is serious long distance and good antenna dimension is ab. 2m. and above.
appropos, how bigger is yours? 28dBi is quite little dish… very small.
A 2 meter antenna 80 meters up is going to be FUN!!! - NOT…
If you could just lift your Side B to ± 80 meters as well you’d be able to establish a good link using normal grids
I’ve done a Fade margin Calc and Fresnel profile and it could work
Let me know if you need some more help.
T
it’s not “FUN!!!”… it is possible. believe me. futhermore, originally mushmx said
… "If you could just lift your Side B to ± 80 meters as " us much more funnest.
Hi everybody
Thank’s for all reply, I continue with this link 
and I read all the post but i have a doubt about what model, kind and mark of antenna i need buy? no matter if is european or american product.
Thanks, best regard. 
Sounds to me like the 350mW cards are broken. We have had this happen MANY times with R52H
yes, every time we replace antenna cables and wless cards. i suppose, it is COMPULSORY when you search what is goin’ on in same case or related.
Hi chvdr and Belyivulk
It’s me mushmx 
thank’s for the reply but what kind and mark of antenna recommend me to use with this link? and if you know some website please post it.
Thanks, best regard.
we have a 58km link here in NZ, with Mikrotik 30DB Dish antennas, R52H, Mikrotik Pigtail & LMR400. We get -69 / -71 for signal
Thanks for the reply Belyivulk
I’m using the next equipments:
2 Routerboard 532
2 Wireless card XTREMERANGE 600Wm
2 Antenna heavy duty of 28dbi
1 tower “AP BRIDGE” 80mts.
1 tower “Station WDS” 60mts.
Distance 64kms.
The situation is very rare because I got a excellent link between TX/RX 60-70 with 18/24Mb transfers but inexplicably the link become degrade until to dead signal and the only reason that come to my mind is that some signal of the airport is interfering with my link 
so I checked all cables, pigtail, router, antenna, etc… and nothing repair the trouble, so I think maybe if I change the antenna to other with more DBI like 36dbi maybe repair the link.
What do you thing about this?
Note. mostly the link cross the jungle and the only build is the airport and we are a sea level.
Heri
What frequency are you using? 57xx?
Have you tried the frequency usage tool? What is your noise floor when the link is good? what does it become when it gets bad? What is the humidity like? What time of day does the link go bad, and for how long. How do you fix it? What type of cable are you using from the pigtails to the antennas? are you weather sealing it correctly?
These are all questions i need answers too, lol
I’m using the band 5.8ghz and frequency 5822
Heri
Try using a lower frequency, 5745, or even to test, set your country to germany and use 5500 (to test only)
If your link stays up you can be sure the problem is interference, if not, you know the problem lies elsewhere
Ok, I’ll do the test the next week.
Thanks Belyivulk 
No worries 
The other thing is time. Does the link go down first thing in the morning after sunrise?
The link go down without matter the time is variable 