Search found 121 matches

by Lee_Wheeler
Mon Nov 28, 2016 8:16 pm
Forum: FM Radio
Topic: 4CX250B
Replies: 8
Views: 1342

4CX250B

What is the consensus on 4CX250B tubes these days? I have not had any need to replace any in at least 20 years and I read some comments here and there that Eimac changed the design at some point to more favor the 450 MHz rigs and they don't do well in FMs any more. I also got a quote on them today f...
by Lee_Wheeler
Sat Nov 26, 2016 7:09 pm
Forum: Everything else
Topic: Wildlife, towers, and security cameras
Replies: 10
Views: 1234

Re: Wildlife, towers, and security cameras

It wasn't on a transmitter site camera but I came across this near my daughter's house.
Deer1.jpg
I nearly wrecked the car I was laughing so hard.

...Lee
by Lee_Wheeler
Mon Nov 21, 2016 7:59 pm
Forum: FM Radio
Topic: Telephone pole antenna mount vendor
Replies: 12
Views: 1381

Re: Telephone pole antenna mount vendor

Lee, doesn't that mean you have to file a modification every year as the HAAT naturally increases? :D Conveniently, most pines grow taller from the top while the rest grows fatter, so you'd be more in danger of the tree slowly eating the antenna. :mrgreen: I brought up the same question at the time...
by Lee_Wheeler
Sun Nov 20, 2016 8:48 pm
Forum: FM Radio
Topic: Telephone pole antenna mount vendor
Replies: 12
Views: 1381

Re: Telephone pole antenna mount vendor

I had a client in East Wanatchee, Washington that mounted the antenna for a Class A on a tree. I had never specified a "Douglas Fir" supporting structure in a 301 before. :D

As I recall he used a pair of chains on a face mount bracket that cinched around the tree.

...Lee
by Lee_Wheeler
Fri Nov 11, 2016 7:49 am
Forum: Radio Studio Engineering
Topic: Obsolete opamp replacement
Replies: 10
Views: 1385

Re: Obsolete opamp replacement

BigRed wrote:
How do you measure the slew rate of a 741? With a stop watch. :)
I think it was in furlongs per fortnight.

...Lee
by Lee_Wheeler
Thu Nov 10, 2016 3:20 pm
Forum: Ask the Engineers
Topic: Offical AMC 8 Transition Thread (was Sat. AMC-8)
Replies: 153
Views: 21759

Re: Sat. AMC-8

^^^This.

I got my email today from Westwood One. Moving to 105 degrees West beginning in February.

...Lee
by Lee_Wheeler
Thu Nov 10, 2016 3:13 pm
Forum: Radio Studio Engineering
Topic: Obsolete opamp replacement
Replies: 10
Views: 1385

Re: Obsolete opamp replacement

TLO81 is a plug and play replacement if you can find them. I think you can find NTE857M through most outlets and they will work as well. It will ignite a slew rate war by the op amp snobs but one of the DEs I had years ago built up a preamp with 30 741 op amps stacked back to back and had a set of S...
by Lee_Wheeler
Sat Nov 05, 2016 6:39 pm
Forum: FM Radio
Topic: Theory Discussion: Circular Polarization Vs. Vertical Polarization
Replies: 46
Views: 4334

Re: Theory Discussion: Circular Polarization Vs. Vertical Polarization

LPFMs, like all stations save some really old grandfathered old 10 watt Class D NCEs, are licensed by ERP, not TPO. Other than some NCE's that had channel 6 television interference problems all FM stations are licensed in the horizontal plane with the choice to have power in the vertical plane such ...
by Lee_Wheeler
Thu Nov 03, 2016 6:39 pm
Forum: AM Radio
Topic: Combining two AMs at one site
Replies: 24
Views: 3090

Re: Combining two AMs at one site

1550 was the array to the South-East of town and it was in horrible shape. They blew a capacitor in one of the ATUs and it took me all day with a chain saw to get to the door on the tuning unit to get in and fix it. As soon as I opened the door it fell off of the hinges. 1550 took a hit in coverage ...
by Lee_Wheeler
Wed Nov 02, 2016 10:47 pm
Forum: AM Radio
Topic: Combining two AMs at one site
Replies: 24
Views: 3090

Re: Combining two AMs at one site

Did you make sure the guy mowing the grass can't take out the new towers like he did on the end tower of the 680 array? :mrgreen: This time we built fences off of the ends of the anchor points. As far as I know they still bale the hay though - a few hundred dollars a year to the beer fund. :D It wa...
by Lee_Wheeler
Tue Nov 01, 2016 8:48 pm
Forum: AM Radio
Topic: Combining two AMs at one site
Replies: 24
Views: 3090

Re: Combining two AMs at one site

I did an interesting one a few years ago where we moved a DA on 1550 into the space between the towers on a DA that was on 680. It wasn't really diplexed but it might as well have been. We stuck a 4 tower 1550 parallelogram in the 1/2 wave space between the towers on the 680 array. The MoM proof was...
by Lee_Wheeler
Sat Oct 22, 2016 5:43 pm
Forum: FM Radio
Topic: Scala FM Antennas
Replies: 8
Views: 1284

Re: Scala FM Antennas

The thing I hate about them is that the Commission licenses them as though they were in a vacuum and they only reference the spec. sheet pattern, no matter how it is oriented with respect to the tower. I have used that to my advantage for clients but I have also had clients get creamed by interferen...
by Lee_Wheeler
Thu Oct 20, 2016 3:51 pm
Forum: Ask the Engineers
Topic: FM radio with excellent selectivity needed
Replies: 13
Views: 1871

Re: FM radio with excellent selectivity needed

Back in the RPU days (Marti remotes were a big reason why I quit being a chief engineer years ago) I had a Crown FM2 in the remote motorhome and it was bulletproof. Now that all of the remotes are done with Comrex units it was safe for me to go back to being a chief engineer again but many of the tu...
by Lee_Wheeler
Thu Oct 06, 2016 4:51 pm
Forum: Radio Studio Engineering
Topic: Spacing XDS units in a rack?
Replies: 4
Views: 779

Re: Spacing XDS units in a rack?

I leave 1 RU between units but I don't know that it is necessary. If you do stack them they should be able to get plenty of air from the sides and an unobstructed air flow out the back of the rack. I have them in a set of racks without open air between the rack units rather than sides and I took the...
by Lee_Wheeler
Tue Oct 04, 2016 1:11 pm
Forum: FM Radio
Topic: Gates Air Flex20 vs. Nautel NV20lt
Replies: 16
Views: 2354

Re: Gates Air Flex20 vs. Nautel NV20lt

Update:

Nautel shipped my client a new VS2.5 and it was installed last night by the local staff with no drama at all. Up and running great and we will see if it stays that way - my bet is that it will be trouble free for years to come.

...Lee