Search found 998 matches

by ChuckG
Mon Jul 08, 2019 10:43 pm
Forum: Ask the Engineers
Topic: Valley 401 schematic
Replies: 4
Views: 263

Re: Valley 401 schematic

No longer needed...I did manage to get this fixed. SSM preamp chip was putting DC on the output bus at higher gain levels.
They are no longer available, but Ebay has plenty.
Unfortunately I could not fix the second unit as someone had "fixed" it before me, ruining the SMD mounting pads.
by ChuckG
Wed Jun 26, 2019 3:04 pm
Forum: Ask the Engineers
Topic: Valley 401 schematic
Replies: 4
Views: 263

Re: Valley 401 schematic

Thanks Bill!
Unfortunately the 401 and 400 have different input sections.

They had the drawings included in the 400 manual but removed them for the 401.
Why do manufacturers do that lol. Really annoying.
by ChuckG
Wed Jun 26, 2019 2:48 am
Forum: Ask the Engineers
Topic: Valley 401 schematic
Replies: 4
Views: 263

Valley 401 schematic

I need one... Seems to have DC on the preamp input. Level pot is scratchy, Overload lights come on when you adjust the control with no audio input applied. Tried disconnecting the 48V phantom source, no change. The +/- 15V supplies are clean. Checked the surface mount caps for shorts, found none. An...
by ChuckG
Wed Jun 05, 2019 10:09 pm
Forum: AM Radio
Topic: Gates One Blows PA Fuses w/ Modulation
Replies: 31
Views: 2056

Re: Gates One Blows PA Fuses w/ Modulation

Can you post the source/specs for those sockets? I maintain a bunch of these...sooner or later...
by ChuckG
Wed Jun 05, 2019 10:07 pm
Forum: AM Radio
Topic: SX 2.5 Won't Power on No Lights
Replies: 10
Views: 315

Re: SX 2.5 Won't Power on No Lights

Nice save! Good reminder to check that stuff.
by ChuckG
Fri Mar 08, 2019 9:09 pm
Forum: FM Radio
Topic: Very low power recommendation
Replies: 20
Views: 713

Re: Very low power recommendation

The problem I had with BW, and I believe I posted it here a while back, was absolute indifference when I needed replacement parts. Had two 300W units pop their Meanwell power supplies. These units were barely 3 years old. BW no longer had stock and told my to "buy new transmitters". I was able to fi...
by ChuckG
Tue Mar 05, 2019 10:38 pm
Forum: FM Radio
Topic: Optimod 2200
Replies: 6
Views: 492

Re: Optimod 2200

Just as a follow up to this, replacing the voltage regulators appears to have fixed it. Guess that should be a standard replacement item with bad caps.
by ChuckG
Sat Mar 02, 2019 9:23 pm
Forum: Ask the Engineers
Topic: Remote Start AEQ BC 500 - Automation
Replies: 10
Views: 329

Re: Remote Start AEQ BC 500 - Automation

Station around here had an AEQ in the production studio. Put it on a good UPS/Surge Arrestor. They're sensitive to incoming power and you'll find repairs difficult to impossible. Sure, you can likely interface it to an automation system, most provide some sort of General purpose inputs/outputs for c...
by ChuckG
Thu Feb 14, 2019 8:33 pm
Forum: FM Radio
Topic: Optimod 2200
Replies: 6
Views: 492

Optimod 2200

Is misbehaving. Runs fine for days...but at some point the input, output and composite meters all pin full scale. When this happens the audio becomes very distorted. Removing audio input, the meters remain pinned full scale. Switching to "bypass" cleans up the audio, but does not unpin the metering....
by ChuckG
Thu Jan 24, 2019 6:09 pm
Forum: FM Radio
Topic: HT-10 APC issues
Replies: 12
Views: 723

Re: HT-10 APC issues

Mark Persons used to repair those by gutting the amplifer and installing a Broadcast Concepts module. Takes just a few hours and a fraction of the cost Take a look: http://www.mwpersons.com/tech-tips/FM/Harris-300-watt-ipa.htm Believe most of those IPA's in the HT-10 are repairable by Silicon Valley...
by ChuckG
Thu Jan 24, 2019 6:05 pm
Forum: AM Radio
Topic: Gates One Blows PA Fuses w/ Modulation
Replies: 31
Views: 2056

Re: Gates One Blows PA Fuses w/ Modulation

I don't recall seeing any on the ones or the fives. I've done the IPA drive measurement many times (scope across a quad resistor, ) and it's safe enough if you are careful. The control and IPA supplies are on but the RF supply should be off. The SX5 has unused thru the bulk head BNCs for making live...
by ChuckG
Mon Jan 21, 2019 6:48 pm
Forum: FM Radio
Topic: Harris HT-10FM freq change
Replies: 5
Views: 316

Re: Harris HT-10FM freq change

Must be the gap between the stub and whatever is around it that is relevant then. I can't find a drawing of the filter anywhere, but there must be some way to modify what you have if you could get the correct dimensions. The odd thing is...Harris calls for the stub to be longer when moving up in fre...
by ChuckG
Mon Jan 21, 2019 1:36 am
Forum: FM Radio
Topic: Harris HT-10FM freq change
Replies: 5
Views: 316

Re: Harris HT-10FM freq change

Can you just shorten the one you have? I'm not remembering what that part looks like.
by ChuckG
Mon Jan 21, 2019 1:32 am
Forum: FM Radio
Topic: Gotta love Westwood One
Replies: 16
Views: 1169

Re: Gotta love Westwood One

I called the WOR network years ago after several weeks of double audio on a weekend car program. The Assistant there basically accused me of being a corncob pipe smoking, shoeless incompetent backwoods Wisconsin hillbilly who miswired the satellite receiver. Until the DoE, (who I have immense respec...
by ChuckG
Thu Jan 17, 2019 12:31 am
Forum: FM Radio
Topic: 100 OHM 100W resistor in Harris HT35FM PA Cavity
Replies: 10
Views: 629

Re: 100 OHM 100W resistor in Harris HT35FM PA Cavity

That's a non-inductive resistor. You should be able to change it to a tab-connector (also non-inductive) replacement without issues if you can't find the circular fingerstock connectors. Surplus Sales of Nebraska has them from time to time too.