> Anyone help me.... I have a 1.2 GHz repeater, but no service monitor or > signal generator for these frequencies. > My service monitor, a Singer-Gertsch only goes up to 499.995 Mhz. I have > tried using the third harmonic in the 420-427 range but either the > service monitor is well filtered, or the signal is too weak to be picked > up by the 1.2 GHz receivers... I have thought about an external tripler > circuit... Any ideas on this or other possible solutions other than > buying a new signal generator (too costly).
I've aligned my repeater using a tripler, consisting of a stripline tuned to 23cm, and using an 1N4148 as tripler (I think - I'd have to open it up). To increase sensitivity, I bias the diode with an 1.5 volts AA cell and an 1Meg resistor, this makes a lot of difference on sensitivity especially on lower input levels. 0dBm of input drive level gives quite some input. If you want, I could make pictures, but don't get too excited over my building practices - I was in a hurry to get the repeater online. 73, Geert Jan PE1HZG
