| Author |
Message |
    
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 548
Registered: 11-2002
| | Posted on Saturday, April 22, 2006 - 8:01 pm: | 
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I'd like to build or add a pre-amp to my Dave boxes.
What parts are needed and how do you go about putting them into a Dave?
Thanks |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2743
Registered: 7-2004
| | Posted on Saturday, April 22, 2006 - 8:47 pm: |
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look at your TS service manual, copy the circuit, add it in & put in a switch |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1190
Registered: 6-2004
| | Posted on Saturday, April 22, 2006 - 10:42 pm: |
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I've never had any luck with receiver amplifiers. Just adding a fixed amount of gain - like the receiver amplifier in CB amplifiers - is virtually useless. They're usually too noisy to actually help pull out a weak signal, and if there is any background noise at all, they amplify that more than the weaker signal.
I've used an amplifier/preselector for SWL and the only reason it's useful is because it has variable gain. You can use just the right amount of gain to increase the weak signal without substantially increasing the noise - sometimes. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 550
Registered: 11-2002
| | Posted on Sunday, April 23, 2006 - 12:26 am: |
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I figured it wouldn't be long before Pat chimmed in.
I'll have to say that the TS amps with their pre-amps work pretty well. Or atleast the ones I've had do. On my base anyway. I've flipped it on and heard things I didn't hear before even on the S9.
But I'll try the TS service manual and see what I come up with.
Thanks. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1214
Registered: 1-2005
| | Posted on Sunday, April 23, 2006 - 10:09 am: |
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I believe it depends on the radio how well a preamp works. On all my Texas Star amps the preamp will bring a S-1 signal to almost S-9 on my Connex and new and improved 148gtl. Now with my 148nwst, Galaxy or Uniden and all my old school radios the same signal will only increase to about S-3 and thats mostly noise. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2748
Registered: 7-2004
| | Posted on Sunday, April 23, 2006 - 11:22 am: |
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hollowpoint's point is very well taken. i have used several ameco & ICE preamps with much success. believe the old ameco is mosfet, & the newer ICE is gaasfet, both were variable.
search the web, 'chop, i know there are others out there. then search for owners manuals/schematics etc & see if it looks copiable.
i have an original boomer 250 from YEARS ago. its preamp is even better then texas stars. never opened it to look at it as to why, but it seems to bring up the signal at a higher ratio then noise. maybe just an illusion, but a good one  |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 551
Registered: 11-2002
| | Posted on Sunday, April 23, 2006 - 4:50 pm: |
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Yeah, I'm gonna check it out right now. I know at one time I took an TS 350HDV I had in my truck and hooked it up in the shack. With the preamp off I couldn't really hear much, maybe a few locals. Then when I pushed it on, I could hear french, I assume from Canada. Regardless, I could hear what I didn't before. So I've often wondered why Dave and the like didn't put them in. I guess keydown boxes don't need them. But then again, not everyone who buys one is looking to keydown all the time.
If TS would build their boxes more like Dave, but leave the preamps in them, I think they'd have a nice box. |
