Denny, It's a Hameg HM5014 that I bought new several years ago. Among its good points are its light weight and compact size, on-screen digital display, built-in tracking generator, ease of use, and accuracy acceptable for most uses. Among its bad points are lack of an external 10 MHz reference input and nonavailability of a detailed service manual.
Shortly after buying this unit, I bought an Eagle return-loss bridge to facilitate duplexer tuning. Without going into the finer points of duplexer tuning, I can say that the Hameg HM5014 is great for tuning notch-only (mobile) duplexers or for rough tuning or checking of cavities in the field, but I prefer to use my HP network analyzer for tuning BpBr duplexers and bandpass filters in my shop. The HP analyzer is heavy, cumbersome, and is better kept on the bench. It, like most of my RF equipment, is referenced to a precise 10 MHz signal from a GPS-disciplined oscillator. Despite its few flaws, my Hameg spectrum analyzer is ideal for the purpose mentioned earlier in this thread, that of viewing the spectrum to see what other carriers are coincident with interference. It cost about $2,000 when new, which puts it in the "economy class" of analyzers, but it offers a lot of bang for the buck. 73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of dgrapach Sent: Wednesday, August 01, 2007 5:04 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Intermodulation Interference --- In Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> , "Eric Lemmon" <[EMAIL PROTECTED]> wrote: > > That last comment about the spectrum analyzer is an excellent suggestion. > Trying to solve such interference problems with cavities or isolators may > involve far more effort and expense than necessary. Here's a case in point: > > I was getting some severe interference to my reception of an Amateur > repeater on 147.210 MHz, but not on other Ham repeaters. My base radio at > the time was a Kenwood TK-760K2, which is a low-tier commercial product. > The interference was sometimes voice, and sometimes data. I could almost > eliminate the interference by putting a DCI bandpass filter in the feedline, > but then I couldn't receive or transmit on the commercial frequencies used > by other VHF repeaters I control. > > So, I pulled out my trusty Hameg digital spectrum analyzer, and set it to > sweep the 140-160 MHz band. As Hi Eric I see you have a Hameg, I thought about getting one, what model do you have , and would you do it again? Will they tune duplexers? Denny ka3sxq
