On 4/17/22 13:08, Bob kb8tq wrote:
The TBolt needs about 16 db in front of it to do a reasonable job. With a 30 db gain antenna and no splitters, that leaves you with about 14 db or so for cable and connector loss. Most of us accumulate multiple GPS gizmos. A 4 way splitter takes your 14 down to 8 db. That puts you “at the limit” with a bit over 100’ of LMR-400.
I currently have three GPS gizmos and expect to hold at that number. I use a GPS Networking LNFA1X4-N filtered amplified splitter spec'd at 0 dB gain/loss. With the side mount option, the worst case cable loss would be around 10 dB, but probably a few dB less. It depends on which available cable I use.
The filter is after the amplifier. However the antenna itself is pretty narrowband. If the filter was in front, getting a 2 db noise figure would be exciting.
Well then, possibly a concern but I suspect a GPS antenna doesn't pick up RF below 500 MHz very efficiently. I guess the only way to know for certain is to try it.
Paul _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
