Search found 45 matches

by REW
Thu Sep 13, 2018 3:58 pm
Forum: AM Radio
Topic: Crystal alternative
Replies: 17
Views: 932

Re: Crystal alternative

Micheal Paton from Baton Rouge, La. had a device for some of the Harris AM transmitters. I think he said it could be set via dip switch to output a frequency of .5 to 5Mhz. I saw the board he had at the Alabama Broadcasters Association convention and it looked professionally made and the price wasn...
by REW
Tue Sep 11, 2018 1:18 pm
Forum: AM Radio
Topic: Crystal alternative
Replies: 17
Views: 932

Re: Crystal alternative

Micheal Paton from Baton Rouge, La. had a device for some of the Harris AM transmitters. I think he said it could be set via dip switch to output a frequency of .5 to 5Mhz. I saw the board he had at the Alabama Broadcasters Association convention and it looked professionally made and the price wasn'...
by REW
Fri Jun 15, 2018 9:36 am
Forum: FM Radio
Topic: National over Eimac or Econco
Replies: 24
Views: 1255

Re: National over Eimac or Econco

Thanks for the info. I got the Econco rebuilt tube. The tube tuned up with no problems. No overloads and loud BANG like the last rebuilds I tried to install. Only problem I had was the grid ring came out when I pulled the old tube out. That made the quick job of changing the tube take 3 to 4 hours b...
by REW
Fri May 04, 2018 10:18 am
Forum: AM Radio
Topic: Need Crystal for LPB-30
Replies: 1
Views: 264

Need Crystal for LPB-30

I am needing a crystal for a LPB-AM30 low power transmitter. 880khz X 6 = 5280khz for the crystal frequency. With International Crystal gone does anyone have any suggestions.
by REW
Mon Apr 30, 2018 9:17 am
Forum: Ask the Engineers
Topic: Temperature Sensor for Remote Control
Replies: 4
Views: 234

Re: Temperature Sensor for Remote Control

I am using the circuit shown except a 12 volt wall wart, at two sites with fairly good luck. It should work well for you if you don't need something real accurate. The LM-34 will give you an output voltage of 10MV per degree F. Example 85 degrees would produce .85 volts at the output. I recommend ru...
by REW
Mon Apr 23, 2018 9:08 am
Forum: Everything else
Topic: A bit of AM History
Replies: 4
Views: 321

Re: A bit of AM History

I worked at one station back in the early 80's where one of the DJ's labeled the transmitter with a marker. It already had the meters labeled at the factory, and if that wasn't bad enough he marked all the pots on the board and then drew a line on the VU meter at 100% and wrote above it " Not above ...
by REW
Tue Apr 10, 2018 1:45 pm
Forum: FM Radio
Topic: FM3.5 odd problem
Replies: 9
Views: 455

Re: FM3.5 odd problem

Thanks for all the help. At about 1am I found the problem. The FM3.5 uses a solid state relay in the primary of the plate xfmr. It seems this relay would start conducting on just half of the AC cycle so it was acting as a rectifier and for just an instance it was putting DC on the transformer primar...
by REW
Mon Apr 09, 2018 2:40 pm
Forum: FM Radio
Topic: FM3.5 odd problem
Replies: 9
Views: 455

Re: FM3.5 odd problem

I took the plate xfmr out of a HT-3.5 and tried it. Did the same thing so that eliminated the transformer. Also no sparks or smoke in the back when it happens. I will try getting the chokes off ground tomorrow afternoon. Thanks
by REW
Mon Apr 09, 2018 12:34 pm
Forum: FM Radio
Topic: FM3.5 odd problem
Replies: 9
Views: 455

FM3.5 odd problem

I am working on an old Harris FM3.5 transmitter that is going to be used as a backup transmitter. I turn it on and It comes up to full power with no problems. Meter readings are very close to the original checkout sheets. After it has been on for awhile it will make a noise that seems to vibrate the...
by REW
Thu Apr 05, 2018 12:24 pm
Forum: FM Radio
Topic: National over Eimac or Econco
Replies: 24
Views: 1255

Re: National over Eimac or Econco

I keep a weak tube as a spare. I know how it tunes and the readings I normally get. If I have a problem with the transmitter I can put it in and if it tunes normally I will know to suspect the tube I pulled out.
Econco told me around 20 days to rebuild a tube on rush or about 25 days normally
by REW
Tue Apr 03, 2018 4:03 pm
Forum: FM Radio
Topic: National over Eimac or Econco
Replies: 24
Views: 1255

Re: National over Eimac or Econco

The Econco NEW tube is also about $700 cheaper than the Eimac. Management ordered a 4CX3500A for me a few years ago and of course they got the cheapest one they could find. They got a PRO-TEK from D & C electronics. I told the boss it probably wouldn't last 3 months. That was 4 years ago and that th...
by REW
Mon Apr 02, 2018 1:53 pm
Forum: FM Radio
Topic: National over Eimac or Econco
Replies: 24
Views: 1255

Re: National over Eimac or Econco

I was thinking about trying a new Econco over a rebuild. A new Econco is what came in the transmitter when it was installed new around 2010.
by REW
Mon Apr 02, 2018 1:23 pm
Forum: FM Radio
Topic: National over Eimac or Econco
Replies: 24
Views: 1255

National over Eimac or Econco

Looking for a YU148 tube for use in an Energy Onix ECO-10 transmitter. I know a new Eimac should be top of the line but has anyone had any experience with the National or new Econco. I have been using Econco rebuilds with good results until last time when I had to get three tubes before I got a good...
by REW
Thu Mar 29, 2018 12:46 pm
Forum: Radio Studio Engineering
Topic: PC to TieLine/Comrex
Replies: 2
Views: 270

Re: PC to TieLine/Comrex

I dont know what Comrex or Tieline equipment you have. We are using the Comrex Access units. I have an App on my phone called LINPHONE. It is a free app and Comrex had the setup instructions on one of the ACCESS web pages. Linphone wants you to create a SIP account with them but it is not needed. It...
by REW
Mon Jan 15, 2018 5:39 pm
Forum: FM Radio
Topic: EO IPA question
Replies: 1
Views: 308

Re: EO IPA question

I have two schematics in my ECO book. One is a 300 watt amp and it does not tell what number the FET is but it refers to a MRF151 on another page. Date on schematic is 1995. No info is given on T2. Another schematic shows a 300 watt amp with a similar schematic using a BLF278 FET. On this schematic ...