the behringer stuff has got me confused a bit.

[N3DRB The Derb]

the audio input to the Raytheon is low Z balanced of course, going into a a UTC line to grid xfmr and then a pair of 6J5's.

The input to any homebrew modulators can now be made the same way since the behringer stuff now basically takes the place of the speech amps I'd normally build? looking for a target input level of roughly + 0~5dbm to the grids of the 6J5's?

I see no reason to reinvent the wheel so I'm going to copy the RA-250 audio input circuit now that I have the stuff to make it ruff.

Mike to behringer, audio chain, then run the output to any transmitter. Can anyone suggest a suitable decent quality line to grid transformer? never had to mess with one before.

snapshot of the RA 250 audio section.....I'll be using different drivers depending on driver power needs. any flaws in this line of thinking?

[N2DTS]

If you have radios that only take line level, its no problem, you can adjust the gain in the radio.

I like the 8 ohms right to the grids and eliminate all that iron, from the mic to the modulator grids is only one (high quality) transformer.

Brett

[K5UJ]

Mike to behringer, audio chain, then run the output to any transmitter. Can anyone suggest a suitable decent quality line to grid transformer? never had to mess with one before.

Derb,
One thing I want to mention before you get too far is that you need some kind of mic preamp between the mic and the Behringer gear to get the mic audio up to line level.  You can't drive the Behringer stuff by hooking a mic directly to it, unless there's something about  it I missed.   Unfortunately a mic preamp is one thing I didn't have a spare of    

Rob

[KB5MD]

I used a Shure 55s mic directly to a Behringer and from there to the audio drivers 600 ohm line level input transformer  in an RCA BTR1.  Maybe your behringer is different
but some of the mic inputs have a preamp built in.

[Steve - WB3HUZ]

Behringer makes many different products. Which model/unit was it?

[W2VW]

The Behringer stuff will take a little time mastering. This is well known among BehRINGer users.

It's still the best bang for the bux.

Keep it cool and consider popping the top if rack mounted. The power splah is one weak point.

Dave in New Jersey. Still waiting for someone to tell me of an alternative to BehRINGer at less than five times the cost.

[KX5JT]

If the unit has accomodation for +48v phantom power for the mic inputs, then I'm fairly certain it has a built in mic preamp.  Heck, if the unit has a "MIC" input at all then I'm fairly certain you're good.  

If you need a mic preamp, ART makes one for 29.99 that works great and gives you a cool old school style VU meter to boot.  It's not rack mount though.

http://pro-audio.musiciansfriend.com/product/ART-Tube-MP-Studio-Mic-Preamp?sku=180581

[Steve - WB3HUZ]

I use an ART mic amp like the one in the photo, except mine does not have the meter. It works FB and has been RFI proof thus far.

[KX5JT]

I use an ART mic amp like the one in the photo, except mine does not have the meter. It works FB and has been RFI proof thus far.

I use one just like the one in the picture and it also does a good job, no problems with RF.

[N3DRB The Derb]

ok, I'll go snag that mike amp.. I cant see building speech amps into the rigs now, just doing all the rigs for the same level and connections makes more sense. ok that helps. just gotta pick out some iron.

oops sorry huz, its the 9024 and the 1024 feedback destroyer pro. there are level buttons on the back of the 1024 labeled -10 dbv and + 4DBu. my guess is I need a mike preamp, feed that into the 1024 and feed the 1024 output into the input of the 9024 9024 into the TX.

[K5UJ]

ok, I'll go snag that mike amp.. I cant see building speech amps into the rigs now, just doing all the rigs for the same level and connections makes more sense. ok that helps. just gotta pick out some iron.

oops sorry huz, its the 9024 and the 1024 feedback destroyer pro. there are level buttons on the back of the 1024 labeled -10 dbv and + 4DBu. my guess is I need a mike preamp, feed that into the 1024 and feed the 1024 output into the input of the 9024 9024 into the TX.

That's correct.  Sorry for the confusion.  The gear I sent is designed for line level audio.  the ART unit looks like a FB mic amp.  Way back several years ago I made the mistake of blowing a lot of dough on a vacuum tube mic preamp.  Works fine but for ham radio I could have probably done just as well at 1/10 the cost.  Year before last I went to Madison Wisc. to attend a live broadcast of Michael Feldman's Whad'ya Know?, a two hour weekly Saturday morning radio program done before an audience that is carried on public radio.  It is sort of like a Midwest Dave Letterman on the radio.  They had great audio for FM broadcast using Neumann KSM106 mics.  After the show I walked to the back of the auditorium to look at the rack of audio processing gear.  There I found a $100 ART equalizer among other things.  I thought that was pretty funny since I was expecting to find all this multi-thousand buck high end pro gear.   But it told me someone who knows something about sound thought ART makes some good gear, good enough to eq a nationally broadcast FM radio show.  I filed that one away.  The eq was something like the ART 45 or 95, can't remember for sure.  They had one or two other things there, some kind of compressor I think, but I can't remember now. 

[flintstone mop]

Brett, Our man DERB, is preparing for install of a broadcast transmitter. There are no level adjustments. That's all done externally.

DON'T modify any circuitry in the Raytheon. The magic will be gone!!
The pro sound equipment of today and hopefully the stuff Rob sent HAS balanced audio............DATS all you needs. You may have to switch the two "hot" wires to get the polarity right. The shield is always GROUND.
'SCOPE needed here!! 0dB at 600 ohms. The Behrigner should do it and the ART mic preamp is a beauty. The feedback destroyer can be your last box in the chain to bring levels up to 0 dB and add some EQ. Maybe a local guru can be there to help you tune in the final adjustments
Did Rob send anything to be like a limiter?
I have sort of changed my attitude toward Behringer. Not bad stuff for a copy of Mackie and it seems well shielded from RF.

Phred

[N2DTS]

I did not know if the rigs he has have level adjustments or not, but they can be added very easy, or the circuit gain could be adjusted to some common level.

At my qth, the line level goes into a two channel power amp with seperate level adjustments, one is set for the 3X4D32 rig, the other goes to the 4x150a modulator, but I can plug it into the 4x100th deck and turn the gain up.  So if I change rigs, I dont have to change anything, its all set.
The flex gets the same line level input, and that radio has a balanced line level gain adjustment, so I use the same stuff to drive 3 rigs without adjusting anything.
I could stuff it into the 32V3 also, but just have a d104 on that...

Brett

[Steve - WB3HUZ]

Yes, you'll need a mic amp or a mixer with mic inputs.

ok, I'll go snag that mike amp.. I cant see building speech amps into the rigs now, just doing all the rigs for the same level and connections makes more sense. ok that helps. just gotta pick out some iron.

oops sorry huz, its the 9024 and the 1024 feedback destroyer pro. there are level buttons on the back of the 1024 labeled -10 dbv and + 4DBu. my guess is I need a mike preamp, feed that into the 1024 and feed the 1024 output into the input of the 9024 9024 into the TX.

[KX5JT]

The ART preamp has both balanced XLR line inputs and XLR and line outputs.  It will feed your mic +48 phantom voltage if required.  It also has a handy dandy phase reverse button.  

[N2DTS]

It makes things a bit nicer if you can stuff all the audio stuff into a desk top rack cabinet that can be grounded.
All the cables are in the cabinet and can be very short, and it clears the desk for the scratch pad.
Its also nice if the preamp has a line level input for the recorder/test generator/etc.

While its not a multi band compressor, the vx2000 does have a preamp, phantom power, line input button, some EQ, etc, in one rack space for $100.00.

It also has lots of flashing lights which is very important.


Brett

[Steve - WB3HUZ]

The ART is a nice little box. I have one, but like Brett, I'd rather have it in a rack.

Derb, Slab has a VX2000 or the predecessor. Talk to him about it.

[KX5JT]

I have a VX2000.  It's excellent.  I don't need my ART anymore except I use it if I want to plug my guitar into my stereo (via a behringer mixer).  I have all my audio (out, that which I listen too) routing through a behringer mixer and then into my Sherwood stereo receiver.  Computer, Radio recievers and the guitar when I feel the need to strum. 

But the VX2000 now takes my Marshall condensor mic audio and does a nice job with some expander/compressor action.  I like it because it doesn't sound overly processed.  Good unit.  They are discontinued however if you search eBay you can find them fairly cheap.  I gave 75.00 for mine and it was just like new, in the box and all.

[N3DRB The Derb]

ok, I'll look into it. I think my little 36" rack on wheels is going to wind up holding rack audio gear for the RA 250 instead of a transmitter. 

I'm starting to get the lay of the land I think. broadcast gear for a broadcast xmtr makes perfect sense. I went and looked at stuff, I can see where you could spend thousands and make it an entire sub hobby just trying for "the perfect sound" just like gitbox playas are always searching for 'the perfect tone'.

cool new worlds. 

[K1JJ]

Derb,

The cheapest way to score a good mic preamp is to go down to RS and pick up one of those FET Op amp chips.  Build it up on a small PCB. There's plenty of circuits on the web. It will take any mic and give you many volts, certainly enuff to drive the Behringer gear.


It doesn't take a lot of money for a professional audio system.

Yep, Dave, I looked at all the expensive gear out there like the Optimod processor and several high end units on eBay. They were all USED and going for $600-$1200++.   I ended up with the Behringer 9024 6-band and their model 3102  31-band EQ.  I paid about $100 for each, the 9024 was used.... great deals. They are definately designed to be RF proof. Never had a problem on 160-10M. (I just tried my rig on 10M yesterday)   Both units are sophisticated and will do anything one needs and more. What bargains.  

O'yeah, and paid $200 for a used ElectroVoice RE-20 that had cartridge baby rattle. Sent it back to EV and they rebuilt it with a NEW cartridge for free. (Lifetime guarantee)  And don't forget the new $95 Behringer 2024 effects box for reverb...        

* So that's about $495 total for a pro audio lineup from mic to output processor, with goodies..

Stu just sent me a brick-wall audio filter for free. Add that on to the audio output for 4-6kc lowpass.. Thanks Stu!


Derb, take a look at the settings for the 9024 on the thread about processor bands. Start with those or any of the preset programs within the 9024.

T

[N2DTS]

Yes, you sure can drop some serious coin for real equipment!
I never did (and you can hear that).
Some guys have access to it being in the business, but all I ever had was very low end crap.
A few years ago, I broke down and got a resonable microphone, before that it was radio shack stuff!
Fooling around with fest junk, pa amps, home audio dbx units, etc, then I got the vx2000, which was very inexpensive.

But I don't think you need to spend all that money to have fun, and can sound very good without it.
I wish I could remember his call, but the best audio I ever heard on the air was a guy running a Sure 55s into a stock 32V3 transmitter.

I have also heard plenty of great sounding guys running a d104 into the rig.

Some compression of some sort seems to help a lot though, just to keep the audio level up and steady.

If someone runs $10,000.00 worth of gear (orbans, etc.) you sort of expect them to sound good, but often I think (to my ears) the D104 into the rig sounds just as good with some guys, or better, but maybe not quite as loud as the $10,000.00 gear guys.

It seems you are not really getting much for $10,000.00 unless you have a really bad voice.....

Brett

[ke7trp]

I had the ART preamp.  Nice little unit.  I gave it away as I needed more inputs.   I use the Behringer 802 mixer. Its real cheap and has phantom power. It sits on the desk and is easy to control. I have dual outputs for the T3 and King.  Also, I have Dual mic inputs.  I can feed the audio out and back in to the Computer if I want to record or play clips back.  Its also nice to have when testing badwidth through the computer. 

So before you buy the little ART preamp, Think about what kind of gear you want to put in place.

CLark

[K5UJ]

Someone has an Orban spring reverb on eBay but it is around $300.