Search found 411 matches

by grich
Tue Jan 01, 2019 12:48 am
Forum: AM Radio
Topic: Gates One Blows PA Fuses w/ Modulation
Replies: 14
Views: 518

Re: Gates One Blows PA Fuses w/ Modulation

I've never worked on a Gates One, but it's basically an SX-1 with many of the mistakes removed... Before the PA fuse blows, is there an obvious imbalance in the PA phases? Follow the procedure in the manual to test in-circuit ALL of the PA MOSFETs and the PDM Amp MOSFETs. Be sure to use a suitable V...
by grich
Thu Dec 20, 2018 4:29 pm
Forum: From the Trenches
Topic: "Help" desk
Replies: 11
Views: 593

Re: "Help" desk

Love talking to first-level support that insist on working the script, even though your introduction to the problem stated all of the obvious first troubleshooting steps had been taken. Perhaps side-tracking the thread, but I've found it interesting that the two most productive IT troubleshooting ph...
by grich
Fri Dec 14, 2018 9:54 pm
Forum: From the Trenches
Topic: Make the whole house shake
Replies: 9
Views: 418

Re: Make the whole house shake

I usually won't be caught dead in an equipment rack during a newscast. Twenty-some years ago I bumped a prompter DA once during a newscast and made it blank for a second. Caught more hell from that (all from the on-air anchor) than the three times I messed up the station signal in front of three dif...
by grich
Thu Dec 13, 2018 5:51 pm
Forum: TV Engineering
Topic: Computer-controlled small L-band switches?
Replies: 9
Views: 613

Re: Computer-controlled small L-band switches?

... I remember thinking, back when we bought the 40x40 Utah AVS-1 back in 1984, that it was big enough that we would never outgrow it... :lol: I think our AVS-1 started out 40x40 mono, then expanded to 60x40 stereo (but only for the first 40 inputs). Full long before I arrived in '94. Kinda miss it...
by grich
Mon Dec 10, 2018 5:03 pm
Forum: FM Radio
Topic: Harris Z FM Diagnostics Failing
Replies: 4
Views: 237

Re: Harris Z FM Diagnostics Failing

So to review, all ISO temps, module current, etc, are about the same? I recall one conversation with Walter that mentioned an occasional issue can be the ribbon cables themselves. I assume you've reseated them all. In some rare instances, they can become intermittent due to air currents moving them ...
by grich
Mon Dec 10, 2018 12:39 pm
Forum: TV Engineering
Topic: Computer-controlled small L-band switches?
Replies: 9
Views: 613

Re: Computer-controlled small L-band switches?

...Did you notice that last month Evertz bought Quintech?... No I didn't...great. :roll: We do use Quintech active splitters and LNB supplies. Rolling your own sounds like a fun project. I had to build up some small perfboards with terminal blocks and optos earlier this year, and I wondered when wa...
by grich
Fri Dec 07, 2018 12:56 pm
Forum: TV Engineering
Topic: Computer-controlled small L-band switches?
Replies: 9
Views: 613

Re: Computer-controlled small L-band switches?

We use Compusat software... I'd give Andrew a call and see what he recommends. You have to buy something he can talk to anyway. :wink: We've never used a matrix control at my TV day-job, all of the receivers we use have four-port switches built-in, and along with active splitters for each dish, we ...
by grich
Thu Nov 22, 2018 9:31 pm
Forum: Everything else
Topic: GOBBLE, GOBBLE!
Replies: 12
Views: 562

Re: GOBBLE, GOBBLE!

I am spending Thanksgiving on-call for my 35th straight year... You old! On-call since 1981...does that make me old too? :lol: I did have one call...someone screwed up a shared video folder. A quick VPN session took care of it, then out to the grill to burn some burgers...the family turkey meal is ...
by grich
Mon Nov 19, 2018 11:17 am
Forum: AM Radio
Topic: KYFR AM tower light monitor
Replies: 16
Views: 703

Re: KYFR AM tower light monitor

RGORJANCE wrote:
Sun Nov 18, 2018 8:35 am
Worked out in SW Iowa on a directional...
There are only a couple of directionals in SW Iowa that I'm aware of...KMA and KYFR. Found any burned-up OIB leads in your TX buildings, Mr. Brockmeyer? :D
by grich
Tue Nov 13, 2018 12:16 am
Forum: AM Radio
Topic: ATU rebuild
Replies: 21
Views: 776

Re: ATU rebuild

Thanks, Deep!

I'll be picking away at this project over the winter in between other problems, but I'll let you all know how it goes.
by grich
Mon Nov 12, 2018 10:57 am
Forum: AM Radio
Topic: ATU rebuild
Replies: 21
Views: 776

Re: ATU rebuild

325 feet of 7/8" foam
by grich
Mon Nov 12, 2018 12:04 am
Forum: AM Radio
Topic: ATU rebuild
Replies: 21
Views: 776

Re: ATU rebuild

I'll accept either a whine or a beg. No need to go overboard. :mrgreen: If you give me a description of the tower and what is on it, I can model it and get pretty close to the right phase shift for optimum bandwidth without having to do a full sweep. Thank you...I won't whine because my wife HATES ...
by grich
Wed Nov 07, 2018 9:55 pm
Forum: AM Radio
Topic: ATU rebuild
Replies: 21
Views: 776

Re: ATU rebuild

Greg, if this rebuild is for KSIB-AM, then I was around when the 'new' ATU got built. I think that it happened when the FM Class A went on the air. The carpenters at the Farmer's Coop built the doghouse and Harold Bauman, the engineer at the time, moved the ATU components from the old decrepit meta...
by grich
Wed Nov 07, 2018 9:32 pm
Forum: AM Radio
Topic: ATU rebuild
Replies: 21
Views: 776

Re: ATU rebuild

An OIB-1 is not going to give you an accurate tower self resistance for a tower with that high an R and X. Design to the last measured tower impedance unless you have a reason to think it has changed. If you have the last measured impedance I hope it was a full sweep, which will let you optimize th...
by grich
Wed Nov 07, 2018 9:18 pm
Forum: AM Radio
Topic: ATU rebuild
Replies: 21
Views: 776

Re: ATU rebuild

DO NOT--repeat--DO NOT try to do this with a "single coil" network. It will be unstable as hell, almost impossible to tune due to the stray reactances and cross coupling between the turns on the coil, and will have shit for bandwidth... Ahhh, yessss! The infamous "Phantom Tee". As stated by others-...