Regarding the ProgRock: "That's the one I'm using with some outboard interface electronics. It can be GPS-disciplined and once the parameters are stored in NVRAM it is very stable." From what I understand, the GPS input is used to set an internal crystal correction factor, but it doesn't seem to be ...

There's a very inexpensive synthesizer / oscillator called the ProgRock, available at qrp-labs.com. It can use a TCXO as a reference for stability of a few parts per million. It covers a range of around 3 kHz to almost 300 MHz. Puts out a 3V square wave. There are actually three separately programma...

Google gave me this file as the very first result.

Bob M.

I don't know why, but 10uF 35V tantalums seem to have the greatest failure rate. Perhaps the dielectric inside is just too thin and they arc over at 35.001V. LOTS of equipment made in the 80s and 90s seems to use dozens of these caps. I know people who just replace ALL of those caps once they find o...

I guess the MX-15 I worked on had no such Axel-fix. I discovered it when checking the frequency response of one of the baseband BNC-jack inputs and was surprised when the unit lost lock and muted. I wonder if GatesAir has anything about this unit on their web site. (I should have known; they only ha...

An MX-15 that I worked on was quite susceptible to very low frequency audio (under 20 Hz) on the audio and baseband inputs. They'd cause the VCO/PLL to unlock due to a sudden shift in modulating voltage, which mutes the exciter. You should check your two units for that and apply sufficient filtering...

I think the additional inward bandwidth is a function of the number of HD sub-channels you have and the sampling rate or quality you've chosen. I don't know what piece of the puzzle controls those (importer, exporter, something else). Since the digital carriers can't extend outward past +/- 200 kHz,...

Which one will you be more likely to get parts for, in the future, like a new PA for the exciter? Safe bet that BE will have replacement parts way longer than GatesAir. Do you need an extender board - that you may not have - to work on the BE?

Bob M.

If you read some of the FCC Part 73 rules, they specify WWV as the primary frequency standard. If they get rid of that, we'll have to use the GPS system, which will make things like 10 MHz GPS-Disciplined Oscillators a lot more useful. One of the nice things about CHU on 3330 kHz is that you can pic...

The lack of 5/10/15 MHz WWV service will mean the end of my Heathkit GC1000 Most Accurate Clock, as that's my primary time device in the house. Yes it draws a lot of power. Yes it gets hot. But you can see those nice red LEDs in a dark room, unlike all the other LCD or analog atomic clocks out there...

Obviously the Radio Cumbre callsign has a much different meaning in Espanol !

Bob M.

I met the station's CE and brought my FIM-41 with me. Both meters were very stable at 1.35mV/m in night pattern, about 5.6mV/m in day pattern. Doesn't seem like much of a null but they both said the same thing, around 1:35pm on a gloomy day. He checked some other points as well and they too were nic...

All that dead air is an unfortunate result of all the automated unattended stations these days. I know of some other Yankees radio network airers that have had similar problems when the board op (back when they thought it was important to have one) headed home during the post-game show but the end-o...

Another "stretch" of the ID requirements that seems to be prevalent in my state, is to have a news break at :15 and :45 and put the "legal" station ID there, even though they have a two-minute commercial break at the top of every hour, where they throw in a promo that mentions the station's slogan/p...

What's annoying is that you might be able to actually FIX the unit if you had a schematic. It could just be a simple interface IC or even a burnt trace hiding somewhere. One cluster where I've done some work has two remote ARC-16 units plus one control unit in the studio. Corporate forced them to go...