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THE AM BULLETIN BOARD => Technical Forum => Topic started by: ka4koe on February 18, 2014, 02:22:08 PM



Title: Timtron Audio Mods
Post by: ka4koe on February 18, 2014, 02:22:08 PM
Well, since I was sick and tired of Timmy fussing at me about my bone stock audio everytime we chatted whilst I was on the Valiant, I decided to go ahead and do the audio mods. Seriously, I was chatting with a guy in Florida the other night. He was on a Valiant that had been modded. It sounded great.

Now, if memory serves, there may be some "gotchas". In particular, there was some concern about oscillation for the feedback mod around the modulation transformer. Are there any other gotchas?

PAN


Title: Re: Timtron Audio Mods
Post by: n1ps on February 19, 2014, 08:35:38 PM
So did Tim give you the sock-in-the-mouth description or the tin can metaphor?   ;D

You will instantly know if you are out of phase with the feedback.

Most people clip the clipper.  Many remove the driver xformer and go with a phase splitter.

On mine I kept the 866s...liked the purple glow of the bad mercury.  I also removed the case.

But there are lot of mods, some on the AM Window.  Doesn't take much to make the Valiant sound better.

BTW...I was in Florida the last few weeks.  I listened in on 75 with a loopstick antenna in the condo.  I have a similar arrangement up here in the northeast that works great.  But it SUCKED in FL.  I barely heard anyone and when I did fades where extreme and rapid. 

Peter


Title: Re: Timtron Audio Mods
Post by: ka4koe on February 20, 2014, 07:48:58 AM
The sock metaphor....


Title: Re: Timtron Audio Mods
Post by: W2VW on February 23, 2014, 11:54:27 PM
Just remember the Timtron mods are meant to be done together and not cherry picked.

Really sad stuff when someone puts up a webpage and tries to pick these mods apart one at a time.

Seems the great myth buster manufactures more myth than fact.

Guy has big problems with Measurements.


Title: Re: Timtron Audio Mods
Post by: Opcom on February 24, 2014, 01:20:08 AM
On mine I kept the 866s...liked the purple glow of the bad mercury.  I also removed the case.

Peter

Do you see purple? I see more blue-ish. I wonder if people perceive the shade of color differently?


Title: Re: Timtron Audio Mods
Post by: KA0HCP on February 24, 2014, 03:14:32 AM
Just remember the Timtron mods are meant to be done together and not cherry picked.

Really sad stuff when someone puts up a webpage and tries to pick these mods apart one at a time.

Seems the great myth buster manufactures more myth than fact.

Guy has big problems with Measurements.
Without knowing who or what you are speaking of (which really doesn't matter)

Every mod should be able to stand on it's own and withstand scrutiny.  Do components behave differently when we don't measure them or run the formulas? 


Title: Re: Timtron Audio Mods
Post by: flintstone mop on February 24, 2014, 06:52:24 AM
Timmy was pretty thorough with mods. I did the entire series for the T-368 and it was pretty nice almost B'cast audio from a T-368 using the stock mod transformer. Changed the excessive capacitance out of the tank circuit for more high end audio, Blocking cap, to remove HV off the tank and the speech amp mods.
I even did the "using a power transformer as a mod transformer" for an Elmac AF67.
Tim can tell long long stories during a QSO.
Fred


Title: Re: Timtron Audio Mods
Post by: W2VW on February 24, 2014, 11:33:07 AM

Every mod should be able to stand on it's own and withstand scrutiny.  Do components behave differently when we don't measure them or run the formulas?  

Yes, electronics 095 is still intact here.

If you drop a 426 Hemi into your Duster and leave the factory tires on the back will it run faster than the Slant 6?


Title: Re: Timtron Audio Mods
Post by: KB2WIG on February 24, 2014, 11:36:18 AM

"If you drop a 426 Hemi into your Duster and leave the factory tires on the back will it run faster than the Slant 6?"

It depends. Does the Duster have that whirley thing painted on the back?


klx


Title: Re: Timtron Audio Mods
Post by: KA2DZT on February 24, 2014, 11:41:16 AM
I had a couple of slant 6s,  only motor you can run without oil.  But, you can't run them without oil forever.

Fred


Title: Re: Timtron Audio Mods
Post by: ka4koe on February 24, 2014, 12:06:25 PM
I've got all the parts ready but will wait until I get finished with another task as the Beast has failed yet again. Some of the OLD coarse loading caps smoked....2 -130s and 1 - 68 paralleled. Probably unequal heating. I was having plate current vs. temp changes so these caps were on their way out.


Title: Re: Timtron Audio Mods
Post by: ka4koe on February 24, 2014, 12:08:16 PM
Used to drive a '66 Mustang convertible, ivy green, black top, Pony interior, styled wheels, Edelbrock intake, Holly 650 carb, tube exhausts, thrush turbo mufflers. My, that was a nice car.


Title: Re: Timtron Audio Mods
Post by: W2VW on February 24, 2014, 12:38:35 PM
I've got all the parts ready but will wait until I get finished with another task as the Beast has failed yet again. Some of the OLD coarse loading caps smoked....2 -130s and 1 - 68 paralleled. Probably unequal heating. I was having plate current vs. temp changes so these caps were on their way out.

With the audio mods properly performed expect peak power to increase. With that increase comes more output tank circuit failures. That's a Valiant.

The good news is Valiants can make almost a kw P.E.P. without breaking parts once a few changes are made. I would not run one that way due to the way it sounds in a diode detector though.   


Title: Re: Timtron Audio Mods
Post by: Pete, WA2CWA on February 24, 2014, 03:04:17 PM
I've come to the conclusion that most Valiant transmitters out there are becoming rigs from hell. Maybe Johnson should have labeled it Valiant SS (for Valiant Satan Spawn).


Title: Re: Timtron Audio Mods
Post by: ka4koe on February 24, 2014, 03:05:18 PM
I agree. I've got to sell it when its fixed. Collins 32V anyone?


Title: Re: Timtron Audio Mods
Post by: N2DTS on February 24, 2014, 03:50:18 PM
The 32V is JUNK!
I had a problem with mine just last week, the plate current needle was sticking.
The thing only went 30 years (as long as I have had it) before it crapped out.
The frequency dial display is also 5kc off, always has been but I never got around to fixing it.

I did just remove the dirt in the meter and its working again, but now I expect it to crap out again.

Junk.
 


Title: Re: Timtron Audio Mods
Post by: W2VW on February 24, 2014, 03:56:33 PM
Phillip, If ya don't like fixing a Valiant don't buy a broken 32V.

Yes Pete, why fix up an old rig when you can hook a noise cancelling mic up to a Flex and have fb audio.



Title: Re: Timtron Audio Mods
Post by: Pete, WA2CWA on February 24, 2014, 04:22:11 PM
Phillip, If ya don't like fixing a Valiant don't buy a broken 32V.

Yes Pete, why fix up an old rig when you can hook a noise cancelling mic up to a Flex and have fb audio.


Absolutely! Life's toooo short!


Title: Re: Timtron Audio Mods
Post by: ka4koe on February 25, 2014, 09:45:02 AM
Ahhhh....another junker. And I was captivated at the thought of a matching transmitter in my rack next to the R388.  So I take it that the 32Vs are WORSE??


Title: Re: Timtron Audio Mods
Post by: ka4koe on February 25, 2014, 09:48:12 AM
On that note, sometimes I LIKE hearing relays click, feel my desk shake, and knob twisting. It appeals to something visceral that escapes and defies description.


Title: Re: Timtron Audio Mods
Post by: Steve - K4HX on February 25, 2014, 09:48:30 AM
No, 32Vs are not worse. They are probably much more difficult to work on but when working, the performance is superior to a Valiant.


Title: Re: Timtron Audio Mods
Post by: flintstone mop on February 25, 2014, 08:31:05 PM
No, 32Vs are not worse. They are probably much more difficult to work on but when working, the performance is superior to a Valiant.
In stock condition the 32V is a very nice transmitter. I do not think you have to do very much for very nice audio.
Yes, hard to work on. Mechanical nightmare, but electronically sound design. 125 Watts out with little strain.
And HEAVY
Fred
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands