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Knowledge
New member
Username: Knowledge
Post Number: 6
Registered: 4-2006
| | Posted on Wednesday, May 10, 2006 - 2:17 pm: | 
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Ok, a little background, Midland 77-285, Wilson 1K mag mount, 575-M6B, Yaesu YS-60, RM KL500 (MRF455s). I cut the 18ft coax that was on the W1K and I didn't have any problems in terms of the SWR...however my SWR fluctuates a by one or two points every 10 minutes that I check it, it could be heat.
My issue, I have all of the above hooked up all times (including the watt meter), and I noticed that while calibrating for my SWR reading, the needle would move just a bit, but when I'd let go of the knob to calibrate, it moved forward. It also did this when I wrapped my hands over the Mic cord. Would you say this is a Ground problem? Would I need to ground the CB, Meter, and the Amp?
Second issue, don't know if this is related. When I key up with my amp inline and on, I can let go and everything unkeys. However, when I turn the amp off, and everything is still inline...I key up and I do my 3.5 watts but when I unkey, it stays keyed at .5 watt. It will not unkey unless I turn the box on and off.
Thanks in advance, any reply will be greatly appreciated. |
Tech237
Moderator
Username: Tech237
Post Number: 333
Registered: 4-2004
| | Posted on Wednesday, May 10, 2006 - 3:12 pm: |
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At a guess I suspect that you have some stray RF floating around.
Check all your cables, your grounds etc. make sure you have good quality coax with a high density braide. Yes ground everything. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2832
Registered: 7-2004
| | Posted on Wednesday, May 10, 2006 - 3:23 pm: |
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did you have this problem BEFORE you cut coax on wilson mount? sometimes you get strange readings if you cut premade lengths on ready made antenna/mount combos.
reflect between the box & radio(try longer jumper?)
bad keying transistor in box
bad soldering/connection at pl259 on antenna
ground problem at amp or mount not 'capacitively-coulpng' as intended |
Knowledge
New member
Username: Knowledge
Post Number: 7
Registered: 4-2006
| | Posted on Wednesday, May 10, 2006 - 5:24 pm: |
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"did you have this problem BEFORE you cut coax on wilson mount? sometimes you get strange readings if you cut premade lengths on ready made antenna/mount combos."
I really hate to admit it, but no it didn't do it.
"reflect between the box & radio(try longer jumper?)"
Minimal.
"bad keying transistor in box"
In the amp? No, because it's when the amp is off and still inline.
"bad soldering/connection at pl259 on antenna"
Not on the antenna, rather on the radio. Could that be it? it just started happening.
"ground problem at amp or mount not 'capacitively-coulpng' as intended"
I didn't understand the coupling part. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1555
Registered: 9-2004
| | Posted on Wednesday, May 10, 2006 - 9:38 pm: |
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first, im going to say that my guess is the PL-259 that you added to the end of your wilson 1000 coax.
if the ground on that connector was not up to snuff, then you are going to have all kinds of goofy problems.
what kind of PL-259 was it?
where did you buy it?
where is your experience level when it comes to installing these things?
you should be using a PL-259 connector with a UG-175 reducer.
the coax braid should be folded over the reducer, trying to spread it around as much as possible.
then you screw on the pl-259, and get out the 100w soldering gun. (dont even try with your 40 watt iron)
you need to hold the gun on the connector long enough for the solder to flow freely THROUGH the holes, not just over them. you will be able to tell that it is right because you can actually see the texture of the braid through the solder.
and you need to do all four holes.
if all this sounds too intimidating; you can try this:
get a good jumper of mini8 or GOOD rg58, that is longer than you need it, and snip off one end.
now you can take apart the base of your wilson, (their site will show you how) and unsolder the old coax, strip the new stuff and solder it in.
not too tough on a wilson.
that way you have a good connector at the other end.
also, describe in detail how everything is grounded.
the capacitive coupling part is how your magnet mount obtains its ground. capacitively.
matt |
Knowledge
New member
Username: Knowledge
Post Number: 8
Registered: 4-2006
| | Posted on Thursday, May 11, 2006 - 1:54 am: |
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"what kind of PL-259 was it?"
I wouldn't even be able to tell you, but what I can say is that I don't think they're of the best quality. They look semi discolored.
"where did you buy it?"
One of the locals...20 with reducers for $20.
"where is your experience level when it comes to installing these things?"
I'm not a guru in anyway, however I've taken a few stabs at it and just can't solder them for the life of me (30 Watt iron). So, what I did was take the braid and fold it over the coax and stuff it into the reducer. VERY tight fit.
"also, describe in detail how everything is grounded."
Yaesu and Midland are going to individual lighter plugs. I have a ground wire (14 or 12 guage can't remember) going from the passenger seat rail (VERY good ground) to the back side of the chasis on each unit. The Amp isn't grounded aside from the 6 inches of 8 ga that it's hooked up with. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1565
Registered: 9-2004
| | Posted on Thursday, May 11, 2006 - 6:25 pm: |
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where does the six inches of 8ga. ground lead for the amp go to?
you really should not be relying on the cig plug for your radio's power.
if you are into this hobby enough to run an amp, you are into it enough to run two wires through the firewall, directly to the battery for the radios power. (might just reduce the static level too!)
where is the amp getting its power from?
a big red light is going off as we speak!
it is to warn us that we have a problem!!!!
stuffing a pl-259 onto a piece of coax might just work at 4 watts, but in the output of an amp?
no way!
youre talking serious RF there my man.
take my advice and either buy a soldering gun 100w or better, and practice, or buy a good coax jumper, and do the antenna soldering thing that i mentioned above.
either way, you need to invest in the gun.
sorry man, i dont mean to be harsh, but that was a MAJOR detail to leave out of your initial post.
hey, at least we've found the problem, and are on our way to fixing it! |
Knowledge
New member
Username: Knowledge
Post Number: 9
Registered: 4-2006
| | Posted on Thursday, May 11, 2006 - 6:56 pm: |
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"where is the amp getting its power from?"
A Huge bolt that holds the passenger seat in. In automotive electronics (MECP rules) a ground longer than 18" should not be used for any amplifier, I don't know if this applies to RF amps, but I applied it anyhow.
The antenna coax is the only one that I screwed up...gotta redo. I'll try that first. I just don't understand why it does it only when the amp is off. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1569
Registered: 9-2004
| | Posted on Thursday, May 11, 2006 - 10:53 pm: |
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you are speaking of the ground. i am asking you where the amp gets its POWER from, the red wire, not the black one.
the short ground wire idea applies here.
if you know its a good ground, then the shorter the better.
remember that even with the amp off, the signal is still passing through it, so a bad connection here will cause problems.
also, you might have damaged the amp by operating it in this condition for too long.
lets just hope for now that thats not the case.
you need to try some changes at this point.
i believe that the ground on that lighter socket is isolated somehow from true chassis ground, and is at least part, if not more of the problem.
a quick and easy test would be to remove the ground wire from the lighter plug, leaving the pos. wire intact, run the ground wire to a bolt on the chassis that is nearby, and plug the plug back into the socket.
anything change?
next change the connector. there are some great tutorials online with bunches of tips for getting it right.
they are not that easy when you first start doing them.
so, amp power? where from?
matt |
Knowledge
Junior Member
Username: Knowledge
Post Number: 10
Registered: 4-2006
| | Posted on Friday, May 12, 2006 - 12:44 am: |
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Amp power is comming from the battery...via 8ga. |
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