problems-swr and transmit

When you say your coax looked good, didja check for continuity with an ohmmeter? It really sounds like there's an open connection in one of the connectors.
If you're not sure how to do this, disconnect both ends of the coax from whatever they're hooked to (antenna, radio, meter, etc.) REad center pin to shell -- should show as "open". Do this at both ends, in case there's a short in one place AND an open at one end. If both ends check OK, now read center pin to center pin -- should show as a dead short, or about zero ohms. Now do the same thing with from shell to shell -- should also show as a dead short.
Do this for each coax jumper.
Unless you've got talkback going and feeding back, the noise is most likely RF from your coax getting into your mic line and producing what's generally called "RF feedback". That's likely to happen if there's an open coax connection, cuz the RF has nowhere else (like the antenna) to go, and it kinda sprays out the unconnected end of the center lead. It won't talk far, but it will have enough field strength to get into your radio just a couple of feet away.
You've got a nice radio, as long as it hasn't been messed with too much. If it's been given the Golden Screwdriver treatment and is putting out junk all over the band as well as harmonics, your SWR will read high because the CB antenna is only designed for 27 MHz (and nearby), but not 54, 81, or 108 MHz. Then, even with good coax, you're likely to show a high SWR because of the signals that aren't radiated by the antenna. As a test, put a dummy load in place of the antenna and see what your SWR is. If it isn't darn near 1.0:1, then there's a problem in the feedline, or one of your meters.
Also, just for grins, try and see if you've got the bad squeal and/or bad SWR when you lower the power on your radio. If it is, then your radio is dirty. Confirm this with a stock CB; if SWR is good, your Galaxy is mistuned. Time to get it to some shop with a spectrum analyzer and a tech proficient in its use.
Hope that helps, and 73.

 

Murph, I wouldn't necessarily dismiss the twist-on connectors out of hand. Most of the connectors I put on are crimp style, and they're typically used up into the low microwave range. However, twist connectors can allow moisture ingress (see below).
I'd suggest doing the ohmmeter test and if it passes, keep them. I'm just not a fan of them myself because I've got a crimp tool that cost $125 and I buy & sell very high quality connectors. Twist-ons are slower than crimping (for me). But surely, twist-ons are more likely to fail (I believe) in an environment that's constantly moving, like a vehicle. In that case, even soldered connectors can fail at the edge of the solder, where it transitions to the braided & flexible part of the coax. Tying the coax down near the connectors can help minimize flexing.
Besides ease & speed of crimp connectors, I also like them because the cable retains its original flexibility. FWIW, I'm used to using crimp connectors for jumpers on VHF & UHF antenna system devices like transmitter combiners and receiver multicouplers. They're used to use one antenna for several transmitters on similar frequencies, and a separate antenna to feed multiple receivers within the same band. That's a pretty critical environment, because most of that equipment is typically found a "busy" site buildings, with *lots* of remote base and repeater stations within a tiny room.

I don't believe soldered connectors are inherently better. They are less expensive for most hobbyists or low volume users to install, because lots of folks have big soldering irons or guns, while good crimp tools are a waste for two connectors a year.

Try listening to 54 Mhz if you've got a scanner to see if you're putting out much signal on the second harmonic. Those signals would be rejected by the antenna and register as a large SWR.

If the coax passes the ohmmeter test, it's still worth it to plug in a stock CB just to compare. If something has aged or changed in your Galaxy, it may now be out of spec, even though it was 6 years ago. If you've got a dummy load, that's a good way to check the coax, too. If you're near someone who has an antenna analyzer, they can eliminate many of the other possibilities by reading the antenna with its own low signal source.

If you decide to cut the connectors off and replace with solder type, cut them off immediately behind the connector, then peel back a little of the jacket and look for corrosion from water coming in at the antenna end. If you've got greenish blue or white powder, start cutting back until it's gone. If it's too short to use at that point, then it's time for new coax anyway.

Cheerio!

 

For the RG58/8X size coax, I've taken to installing clamp-type BNCs on the cable, and using BNC to PL259 adapters. With clamp type, you only need to solder the center pin; the shield connects with a big ole compression fitting.

The advantage of BNCs is that when they are connected, the connection is waterproof. I would still wrap any outside connections with Rescue Tape, though, as you never know the quality of the adapter.