Search found 32 matches

by radio_guru
Sun Jan 07, 2018 9:13 pm
Forum: Ask the Engineers
Topic: Convert to LEDs, or leave 110v?
Replies: 10
Views: 508

Re: Convert to LEDs, or leave 110v?

I did just that with some RCA replica fixtures. I procured 1M long strips of NFLS-R300-X3 series red LEDS from superbrightleds.com Super bright emission. Blindly bright In my fixtures, I went one step farther. I also installed strips of amber and "wig-wag"d the amber and red using a flasher from: ht...
by radio_guru
Fri Jan 05, 2018 8:40 pm
Forum: FM Radio
Topic: Tower Painting question
Replies: 13
Views: 394

Re: Tower Painting question

In the past, I have used a moisture cure urethane paint from a company named Wasser High Tech Coatings. I get 10 years solid out of the orange before it softly fades to a greyish pink. The model is MC-Luster Shield Coat 100 --GLOSS... Gloss paint is per AC-7460-L., Section 12. As are the paint tint ...
by radio_guru
Tue Jan 02, 2018 11:22 am
Forum: FM Radio
Topic: RF Spectrum Analyzer
Replies: 25
Views: 866

Re: RF Spectrum Analyzer

If you have access to $3400K US, the following unit (Anritsu MS2721B) will do the job with the proper accessory external notch filters. It's essentially an updated portable version of the HP8594E with tracking generator and a few added features. I now own both model devices. The seller will accept $...
by radio_guru
Mon Jul 17, 2017 1:15 pm
Forum: FM Radio
Topic: Static Dissipators?
Replies: 13
Views: 1348

Re: Static Dissipators?

I'll second the ERI lightning spurs. Put them on all my towers so far and the hits have been fewer and farther between. And at the same time beefed up the earthing system so the resistance would be lowest as well. And like others have opined, lightning will go where it wants and how. So if the spurs...
by radio_guru
Mon Jul 17, 2017 9:34 am
Forum: Radio Studio Engineering
Topic: SIP lISTEN LINE
Replies: 0
Views: 356

SIP lISTEN LINE

To the Braintrust, Have a client who employs a good VoIP Asterisk/FreePBX system and Polycom phones who wants to add listen lines for their stations OTA and outbound network feeds. They have standard telco TDM-PRI type service and converts to SIP in-house. So the quality of the service is not degrad...
by radio_guru
Tue Jun 27, 2017 5:29 pm
Forum: Ask the Engineers
Topic: Offical AMC 8 Transition Thread (was Sat. AMC-8)
Replies: 153
Views: 12742

Re: Offical AMC 8 Transition Thread (was Sat. AMC-8)

Anyone installed the new MAX receiver from Orbital Media (old CCS) to replace the SGIII as part of the AMC18 conversion?

What are your thoughts on the difference in audio quality between the two systems?

RG
by radio_guru
Tue Jun 27, 2017 5:25 pm
Forum: Radio Studio Engineering
Topic: EAS Issue
Replies: 13
Views: 1210

Re: EAS Issue

In our group, the EAS is after all switching regardless of whether we're operating in AoIP or conventional. Insertion is after the delay, all pre-processing, emergency bypass switches, everything. We use a pair of TFT 940 multi-station insertion units for feeding four stations just before each stati...
by radio_guru
Fri Feb 26, 2016 1:39 pm
Forum: FCC Discussion
Topic: ASR for towers holding unlicensed WISP equipment
Replies: 11
Views: 1297

Re: ASR for towers holding unlicensed WISP equipment

Not any more. The revised Part 17 rules released last year places all responsibility on the structure owner. Also, it doesn't matter whether the radio systems on the structure are licensed or Part 15. It is urban legend Part 15 is exempt. It is not. The radio systems are authorized under any Part, a...
by radio_guru
Fri Feb 26, 2016 1:28 pm
Forum: FM Radio
Topic: ICE Prevention - Radomes or Electric De-icers?
Replies: 17
Views: 1556

Re: ICE Prevention - Radomes or Electric De-icers?

I am a radome guy. I've had both heaters and radomes and prefer the latter. Heaters fail and you never know one or more fail until you need them. The heaters need a control system, constant monitoring, and a cr*pload of AC power. Conductors which are a DC path right into your service panel (lest you...
by radio_guru
Tue Nov 24, 2015 7:00 am
Forum: STL Engineering
Topic: Receiver Preamp?
Replies: 8
Views: 1462

Re: Receiver Preamp?

Let me add, with broader front ends come off-channel overload and desense. Such as from paging and cellular who might be close by and/or within the main lobe of the RX antenna. I have found adding a good bandpass filter cleans up a lot of perplexing anomalies. Particularly with digital systems. Case...
by radio_guru
Fri Nov 20, 2015 10:04 pm
Forum: AM Radio
Topic: What is the typical complex Z for a 1/4 wave vertical ?
Replies: 6
Views: 1146

Re: What is the typical complex Z for a 1/4 wave vertical ?

If you have a real network analyzer with a power amp and the proper directional couplers, you can overcome the ambient RF. We did a 6 tower DA with a Class A 50KW only a couple miles distant. On site field was something north of 1.5V/M. Same thing for doing tune-ups in the Meadowlands where no one s...
by radio_guru
Thu Nov 12, 2015 8:33 pm
Forum: AM Radio
Topic: WCFJ Gone dark, everything passive for sale
Replies: 2
Views: 803

WCFJ Gone dark, everything passive for sale

Folks, I'm relaying this for Mike McCarthy, the DoE of Newsweb in Chicago. He advised they're planning to dismantle the TX site, re-built with all new gear in 1999. Everything after the TX is being sold except the CPB-1. That would include: KTL-- 3 cabinet phasor w/ TCT/EXR-5 and internal 1KW dummy ...
by radio_guru
Thu Nov 12, 2015 8:04 pm
Forum: FM Radio
Topic: Harris Z-10 PSU mod (long post).
Replies: 12
Views: 2501

Re: Harris Z-10 PSU mod (long post).

I don't know if this thread is still active or if DaveK is till looking at this thread, but I have three of these beasts and (know of several more) with some problematic rectifiers. I'd like to know if you have any left and cost. Chris, can you send this note to him with my listed e-mail address? Se...
by radio_guru
Tue Mar 31, 2015 1:45 pm
Forum: FM Radio
Topic: lightning arrester
Replies: 6
Views: 957

Re: lightning arrester

Never use braid for lightning and surge suppression. If you look at nodal analysis of braid, every strand carries RCL in a large parallel circuit. And moreover, each 26ga. strand is a fuse. And further, braid is fragile relative to THHN or strap. And still further, using braid outside (as in the cas...
by radio_guru
Tue Mar 31, 2015 10:15 am
Forum: FM Radio
Topic: lightning arrester
Replies: 6
Views: 957

Re: lightning arrester

I echo the absolute need to bond the mast or supporting structure to earth via a driven electrode and suitably heavy conductor as a starting point. Preferably at least 10ft. long x 3/4" and copper plated steel rod. That rod is available at just about any electrical house as well as Home Depot. Use #...