Search found 504 matches

by kcbooboo
Fri Sep 14, 2018 4:30 pm
Forum: AM Radio
Topic: Crystal alternative
Replies: 17
Views: 864

Re: Crystal alternative

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 ...
by kcbooboo
Thu Sep 13, 2018 5:26 am
Forum: AM Radio
Topic: Crystal alternative
Replies: 17
Views: 864

Re: Crystal alternative

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...
by kcbooboo
Fri Aug 31, 2018 7:05 am
Forum: Ask the Engineers
Topic: Cablewave Part No. - N Female for FLC78-50
Replies: 9
Views: 204

Re: Cablewave Part No. - N Female for FLC78-50

Google gave me this file as the very first result.

Bob M.
390.pdf
(53.99 KiB) Downloaded 18 times
by kcbooboo
Tue Aug 28, 2018 4:01 am
Forum: Ask the Engineers
Topic: Tantalum caps
Replies: 9
Views: 283

Re: Tantalum caps

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...
by kcbooboo
Mon Aug 27, 2018 3:41 am
Forum: FM Radio
Topic: The-1 or FX-30
Replies: 17
Views: 570

Re: The-1 or FX-30

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...
by kcbooboo
Sun Aug 26, 2018 4:08 am
Forum: FM Radio
Topic: The-1 or FX-30
Replies: 17
Views: 570

Re: The-1 or FX-30

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...
by kcbooboo
Tue Aug 21, 2018 5:34 am
Forum: Digital Radio
Topic: Nautel Extended Digital Mode
Replies: 5
Views: 484

Re: Nautel Extended Digital Mode

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,...
by kcbooboo
Sat Aug 18, 2018 5:48 am
Forum: FM Radio
Topic: The-1 or FX-30
Replies: 17
Views: 570

Re: The-1 or FX-30

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.
by kcbooboo
Fri Aug 17, 2018 5:36 am
Forum: Everything else
Topic: WWV WWVH
Replies: 16
Views: 636

Re: WWV WWVH

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...
by kcbooboo
Wed Aug 15, 2018 5:29 am
Forum: Everything else
Topic: WWV WWVH
Replies: 16
Views: 636

Re: WWV WWVH

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...
by kcbooboo
Thu Jul 26, 2018 1:46 pm
Forum: Everything else
Topic: WKRP
Replies: 16
Views: 545

Re: WKRP

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

Bob M.
by kcbooboo
Mon Jul 23, 2018 1:22 pm
Forum: AM Radio
Topic: Wavering field intensity
Replies: 9
Views: 503

Re: Wavering field intensity

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...
by kcbooboo
Wed Jul 04, 2018 3:36 am
Forum: AM Radio
Topic: Anyone Home?
Replies: 13
Views: 564

Re: Anyone Home?

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...
by kcbooboo
Tue Jul 03, 2018 3:21 am
Forum: AM Radio
Topic: Anyone Home?
Replies: 13
Views: 564

Re: Anyone Home?

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...
by kcbooboo
Thu Jun 21, 2018 5:39 am
Forum: Ask the Engineers
Topic: Burk ARC-16 help
Replies: 11
Views: 408

Re: Burk ARC-16 help

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...