[NLRS] Ericsson 902 amp question

[Chris Elmquist]

It's the Radio Frequency Test Loop which is apparently a port that
allows RF to be tapped from the amp and fed over to a receiver in
the cellsite so that some kind of automated testing can be performed.
There's a jillion patents out there covering use of said port for various
automated test scenarios.

I suspect it is a tap (directional coupler) that just samples the output
at some standard level.

Here's one reference to it:

http://www.patentstorm.us/patents/6434364-description.html

	One conventional automated test method, known as Radio Frequency
	Test Loop (RFTL), provides a loop between the transmitter and
	receiver paths of a base station. In a test mode, RF switches,
	connected to suitable attenuators, couple the transmitter of the
	base station to its receiver to test base-station receiver and
	transmitter paths. The RFTL, however, provides for the testing
	of some but not all elements within the system. For example,
	the RFTL method does not include base station antenna and feeder
	in the test loop. As a result, if an external object, which is
	positioned near the base station, impedes propagation of RF waves
	to and from the base station, or if the antenna has been damaged,
	the RFTL method is unable to accurately detect reception quality.


Chris NØJCF

On Monday (01/15/2007 at 11:11AM -0600), Bill K0AWU wrote:
> 
> 
>   What is the "RFTL" connector on the CMS 88 Ericsson 900Mhz amplifier 
> front panel??
> 
>   Still hoping to be available on 902 next weekend. Waiting on a 24V 
> switching supply .... sequencer interface is complete except for one switch 
> that is coming with the power supply.
> 
>   The interface will allow the SDReceiver to to be used on 902 as well as 
> 2m and 10Ghz... 
> 
>   I have a 10elem "cheap yagi" side mounted on the tower at 55ft pointed 
> toward EN34/35 .... Gary GHZ with his 40w has good CW copy the 
> several times I have listened for him  5-2-9. Feedline is LMR400.

-- 
Chris Elmquist
mailto:chrise at pobox.com