XVGA Monitor AB Switch Build or Buy?

[MAKeller]

This type of AB switche (those that can switch UHF signals) are usually expensive.
What bandwidth should I desgin too? Are there any commerical units available under $25.00 US? Build for Buy?

 

[xxargs]

This type of AB switche (those that can switch UHF signals) are usually expensive.
What bandwidth should I desgin too? Are there any commerical units available under $25.00 US? Build for Buy?

Old days with only 640x480x60 Hz VGA is easy to make switch, but now with 1400x1050 and 85 Hz and higher, you need handle with care.

pixel clock goes upp to 200-250 MHz and need handle with RF-eye including impedans control....

most importent factor is cable, switches, connectors etc. have 75 Ohm impedance whole way without discontinitue - discontinitue give reflexes and shadows on monitor.

(remember modern VGA-stream is a analog stream transporting up to 250 Mbyte/s (2 GBit/s) information on each stream, 3 times in paralell - your Ethernet handle only 100 Mbit/s to compare... and you willing to handle this on cheapest possible switches and still want high quality of monitor picture???... )

Short distance reflexes (< 1m) give a unsharp text on screen and long distance reflexes (> 1m) give shadows...

Is a mechanical stuff and high precision of geometry whole way, special switches and not easy to day to build whith low price and still high quality...

Possible better to find electronic switchboxes with videoamplifier and electronic video switches for better impedance control (to supress reflexes) but need handle frequence range from 60 Hz to 300 MHz without distorsion and attenuate on high frequency...

look on Maxim circurits if you decise to build itself.

 

[echo47]

All the store-bought VGA switches I've seen are absolute junk. Total disregard for RF signal integrity. If anyone has found a good one, please tell us! A full KVM switch would be especially nice.