Is this possible ?

dr sportster

Well-known Member
Got a new audio turntable for the shop and it seems the stereo volume does not get as loud as before. I also have a racist trucker N wording and cussing bleeding into my speakers with the stereo off . I hope he was just passing through.
 
I've noticed, throughout the years, that different turntables have different levels of internal amplification.... if any at all. Just depends on what system they're a component of. If the player was sold as an accessory for any stereo, it usually has a decent amplifier built in. Usually. Not sure if an in between preamp can still be had. Everyone usually just made their own, or pitched the offending unit for a better one. As for the ugly mother trucker, was the bleed through heard when the tt was being used or over the radio? Either or, band filters used to be available through Rad Shak. They're all gone, so whatever electronics resource that's available to you should do.

Mike
 
Sounds like that guy has a lot of heat going to his fire stick. Hopefully it's a truck that is in your area on occasion & not a home base in th area. Should be able to get some use from a FM filter either way.

Mike
 
On the audio, what Fawteen said is a likely culprit.

As far as the bleed through from the trucker, do a search for Citizens Band band pass and band reject filters. Been so many years since I did that kind of work, I couldn't begin to suggest a supplier, but somebody out there ought to carry them.

When I was a kid, we went to church in town and about a block away was an AM radio station. The radio station signal used to overload the church's PA system and suddenly bleed through the PA system at random times. This was in the days of tube type amplifiers and I'm sure it was not a very sophisticated PA system. Made for some interesting sermons.
 
That is RF pick-up from a high-powered CB radio which is illegal but most truckers use the high power. Make sure your connecting leads are shielded cable and that your amplifier is grounded. Sometimes it requires small bypass capacitors on the input and RF chokes or ferrite beads on the leads. I remember a similar case where a foul mouth got in a church amplifier one Sunday.
 
Right you are, some really good turn tables are equipped with a magnetic cartridge. They usually put out a small. maybe only millivolts, where a crystal cartridge may put out 500 to 1000mv A preamp is needed. Shielded cables to the preamp is also needed to prevent picking up Cb truckers and other static, as the preamp will likely amplify that as well. hey make much better sound, and records are less damaged by playing.
 
Yes it is possible for a CB to demodulate within a stereo especially if the output amplifier is single ended. Not so much for a push-pull output amplifier
 
Mr. Nicholson has it right. Likely different cartridge type with output below typical "line level". Some of the older reciever/amps had built in phono pre-amps.

I've had the issue before and eventually bought a seperate phono pre-amp with adjustable output and also contained switchable low frequency filter (to cut rumble if necessary) and led indication to warn when you get into clipping.

Something on the order of these here:
Phono pre amps
 
If your old turntable was a cheap one, it probably had a ceramic cartridge with a higher output than a good magnetic cartridge. But in that case the volume would be MUCH lower with the new turntable, almost inaudible. A more likely explanation is the old turntable cartridge was of the moving magnet type, while the new one is moving coil. My stereo receiver has a switch for either type. I just took a look at the phonograph preamps that are available, and it looks like they all have line-level outputs, which means you'd have to plug them into the aux or tape input of your receiver, which would be a problem if you don't have a spare input.

There are also products sold as "moving coil transformers", which seem to be absurdly expensive.

Another option would be to replace the moving coil cartridge with a higher output one. You could use a moving magnet cartridge, but there are also high-output moving coil cartridges that are intended for use with older stereo equipment that isn't designed for MC cartridges.

Or maybe it's time for a newer stereo receiver. That might be the best solution; by the time you buy a preamp or different cartridge, you're a quarter of the way to the cost of a receiver.

As for the interference from your trucker buddy, there's probably not much you can do on your end. A different phonograph cartridge might help. If he continues to be a problem, I'd report him to the FCC. If he's running an amp on CB equipment, the FCC will come down on him. If he's a licensed ham operator (unlikely), he can legally operate at up to 1500 watts, but the foul language will get his license pulled.
 
The one that broke was a Fisher . The new one is a used Pioneer. There are no receiver bargains in local pawn places.
 
> The one that broke was a Fisher . The new one is a used Pioneer. There are no receiver bargains in local pawn places.

Fisher equipment was of reasonable quality, so it probably had a moving magnet magnetic cartridge. What I would do is to swap the cartridge from your old turntable if you still have it. If that fixes your volume issue, then you can decide whether to keep using the old cartridge or buy a new one with the same specs as your old cartridge. If that was the original cartridge, the stylus is probably long overdue for replacement. Even if you can find a replacement stylus, it would cost about as much as a complete cartridge.
 

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