Month: February 2013

God bless the HP 8924C: without you poor college students would not be able to possess RF test equipment way above their pay grade. My model is the 60 W continuous version, US with green CRT. I was able to secure this wonder for $869 shipped from Washington to Boston, MA on eBay. It also seems like my purchase raised the price of these units on eBay by $200-$500. Sorry. Mine is in “Almost New” condition despite being over 17 years old. It originally retailed for $30,000. Pretty cool stuff. It cost more than cars back then.

In the picture, you can see it dominating my dorm room desk (room mate is thrilled, obviously). It’s huge and heavy and says “TWO PERSON LIFT!” on the side. I have also officially named it “Bruce.” Continue reading God Bless the HP 8924C: A Tale and Tutorial of the Service Monitor

The Motorola i50r is a rather archaic device produced by Motorola in the 1990s for use in controlling simple repeaters while allowing telephone interconnect functionality, remote setup and knockdown of the repeater, and a few other simple functions. It is, in essence, a repeater controller that can be setup in minutes with a few dip switches on the front and runs reliably. Its most important feature is that it provides telephone interconnect or autopatch in a pretty slick and efficient way. Its one big shortcoming is that it lacks an automatic identification feature, so your repeater will be going stealth. (Please refer to FCC or applicable regional rules/regulations regarding the legal operation of your repeater. The axfp.org enterprise is not responsible for your illegal actions while using this device.)

Continue reading A Tutorial on the Motorola i50r Basic Telephone Interconnect Repeater Controller

Background:
This was purchased from jaco3378 on 1/12 with tuning service. Shipped the 18th and received the 29th to Boston, MA.

I ordered a Motorola “duo-repeater” at the end of 2012. It consisted of two SM120 radios and came with two antennas, something I later learned was not a fantastic way to make a repeater. The high power of the transmitting antenna would “de-sense” the receiver of the repeater (I assume some early gain stage is overloaded by the high level of the nearby signal and some gain control effectively reduces the level of your intended signal into the receiver). Continue reading Updated: Repeater on the Cheap: The Chinese SQ-450N Duplexer Test Results