OH NO! MFJ 828 PROBLEM.

[Sonar]

Before anyone scolds me I was warned about purchasing anything MFJ but, I didn it anyway. It is under warranty and I returned it but, no problem was detected. It's being returned to me but there is no doubt I'm still going to have the same issue that I sent it out for. I'm going to have to assume there's something on my end causing the meter to act like it does. Okay here goes!

I'm using a Madison in concert with a phantom triple stage (800) for ssb hooked up to a Dawia two position switch to operate a sonar fs 2340 with a Palomar 300a (500) for my AM use My antenna is an iMax 2000 with an MFJ 915 of choke and LMR 400.

When I key either the Madison or Sonar with the amps in stby the meter works fine.
About 2 watts on Am for the Sonar and, 2 watts AM and 15 on SSB with the Madison.

Once I take either amp off stby the anolg cross neddles on the mfj 828 open as wide as possible.
The neddle on the right side slames into the right of the meter and the left into the far left side of the meter.

The alarm sounds and the digital swr section of the meter shows an swr that's off the charts.
This lasts for about a second or so than the cross needles drop down to correct swr (1.2:1) and output as, does the digital side of the meter.

I thought that there might be something wrong with the auto wattage (output) recognition circuitry inside the meter.

I sent the meter back to MFJ and it was tested. According to Joe at MFJ there's nothing wrong with the meter. There's no doubt the problems going to continue.. Its as if there's no antenna in line for the second the meters figuring out how many watts is going through it.
I've watched YouTube clips of that same meter with a thousand Watts being applied to it and what happens to my meter does not happen to the meter on YouTube.
The one on YouTube reads the correct output and SWR instantaneously (upon key down) opposed to taking some time to recognize output. For a second it seems as if there's absolutely no antenna in line.
I'm afraid that until the meter figures out the amount of wattage going through it I'm going to damage my station.
I've listed my station and everything excerpt the Mic's, which I don't think matter in this case.
If anyone has an idea as to why this is happening please share with me.
MFJ. Live and learn. Thank u all.

 

[loosecannon]

just guessing here, but are you using the same mic with both radios?

you stated in your post that as soon as you take the amps off of standby, the meter goes crazy for a second.

im assuming that you mean that with either amp in operate mode, when you key the mic, the meter goes crazy for a second or so.

is that what you meant?

or are you saying that the meter goes crazy upon switching the amps in to operate mode and it has nothing to do with keying the mic?

have you taken the daiwa switch out of the equation in order to isolate the problem to the MFJ unit?

it could be that the daiwa switch has a problem.

the more info you can give, the better advice you can get.
LC

 

[fourstringburn]

I tried to use those MFJ- 915 before and had nothing but bad luck with them. Some actually changed the impedance much I couldn't even use an auto-tuner to tune it.

More than likely it is common mode currents affecting your meter and it is multiplied with the amp on.

I do suggest using better baluns. I use Better balun designs 1:1 feedline isolators and never had a problem since. They are more expensive, but you get what you pay for.

http://www.balundesigns.com/model-1116di-hf-low-band-optimized-1-31-mhz-5kw/

 

[midnight special]

do you have power on to the amps?
i have a problem where if i key a cb up in my truck the 10 meter amp will key even though it is not in line with that antenna,,,, i have to remember to shut amp off to keep it from doing that,,,, if you have both amps on i think that is your problem,,, think making sure one amp is off and in standby might help

 

[wavrider]

Radio-amplifier-meter-antenna.

Eliminate all the switches and associated cables and you will eliminate your problem.

To many loops in your set up.
OR do some proper RF grounding, maybe then you will eliminate the problem.

 

[Road Squawker]

Well, you certainly bad mouthed MFJ lot, but,..... I have a feelin that it's not an MFJ issue.

 

[Sonar]

just guessing here, but are you using the same mic with both radios?

you stated in your post that as soon as you take the amps off of standby, the meter goes crazy for a second.

im assuming that you mean that with either amp in operate mode, when you key the mic, the meter goes crazy for a second or so.

is that what you meant?

or are you saying that the meter goes crazy upon switching the amps in to operate mode and it has nothing to do with keying the mic?

have you taken the daiwa switch out of the equation in order to isolate the problem to the MFJ unit?

it could be that the daiwa switch has a problem.

the more info you can give, the better advice you can get.
LC

I use a silver eagle with the Madison and a non Amplified d104 with the sonar. The meter goes crazy for a second immediately after my initial Key. That happens on either station. I haven't received it back yet and believe it or not that's the only thing I could think of. To remove the 2 position switch I have. I enjoy using the dawia to switch between setups and hope its my switch and a new switch won't do the same thing. I will see what happens after I remove the switch. The switch itself works fine with other cheaply-made non pep reading meters (Workman/RadioShack). With all the electronics in the 828 I suspect that something on my end is causing the issue. I totally believe Joe at MFJ. He says the meter is working fine. I'm hoping it's the dawia and a new one will fix the issue. Thank you loose cannon much appreciated.

 

[Sonar]

Radio-amplifier-meter-antenna.

Eliminate all the switches and associated cables and you will eliminate your problem.

To many loops in your set up.
OR do some proper RF grounding, maybe then you will eliminate the problem.

I have no rf grounding at all. I'm in a room with no where to ground. Whether this is the problem or not I'd like to ground my setup never the less. Any suggestions? How do those artificial grounding devices work? Thanks

 

[Sonar]

do you have power on to the amps?
i have a problem where if i key a cb up in my truck the 10 meter amp will key even though it is not in line with that antenna,,,, i have to remember to shut amp off to keep it from doing that,,,, if you have both amps on i think that is your problem,,, think making sure one amp is off and in standby might help

No. I only use one setup at a time. There's never two ams or transceivers on at the same time.. I suspected it was the dawia switch unfortunately it didn't occur to me until I had already sent the meter back to MFJ.

 

[Sonar]

Radio-amplifier-meter-antenna.

Eliminate all the switches and associated cables and you will eliminate your problem.

To many loops in your set up.
OR do some proper RF grounding, maybe then you will eliminate the problem.

Waiverider..Do you believe the switch and extra cables will cause the problem even with a new switch? What I'm asking in a verbose way is no matter what I need to eliminate the dawia and extra cables needed to use the switch, correct? Thanks

 

[wavrider]

Sonar I am not at your station to see exactly how it is acting as far as the problem you are experiencing.

I personally only have one station connected at a time due to the possibility of having RF loops or, GASP, a switch going bad and transmitting into another receiver.

I have used B&W switches with good results but only to connect to antennas, not from different rigs to one antenna.

The daiwa switch may or may not be causing your issues.

Once you get the meter back a simple process of elimination will determine the culprit.

I have seen stranger things happen when it comes to RF.
Friend of mine in Atlanta was experiencing severe rf problems on his station with the amp in use. Turn the amp off and no issues.
Turned out his DC power lead was roughly 9 feet long as his PS was down the bench from the operating station. He shortened the Power lead and cured his RF problems, the Power lead seemed to be acting as a resonant antenna.

 

[midnight special]

buddy here said to use a switch that grounds the one out let not used,,,,,and make sure switch is grounded good..... he said something like the old heathkit coax switches where the ones not used get grounded,,,,,,

 

[loosecannon]

the reason i was asking about the mics is because D104's can have a loud "click" to them when you key them, and i was wondering if that was causing the meter to slam the needles.

if you turned your mic gain all the way down, and tried keying up, you would know whether or not this was the problem.


however, after reading your second post, it does seem like a stray RF problem, and sadly, that can be much harder to track down.

the best thing you can do at this point is to do some testing by removing different parts of the station, or changing coax cable lengths between certain items, and noting any changes in performance.

the notes are especially important, because it's all too easy to forget a change that you made.

for example, say you have a six foot coax jumper going from the amp to the antenna switch.
try a three foot jumper here. note any changes, and then change it back to the six foot jumper, and try a different length jumper between the radio and the amp. again,noting any changes.

you have to be methodical about it, and only change one thing at a time, then test, then put it back the way it was, and then change something else.
do this over and over, and you will start to see a pattern in your notes, like, every time this six foot jumper is used after the amp, the meter goes nuts, but when it's used from radio to amp, everything is good.
this would mean that particular jumper may have an RF leakage issue, such as the outer shell of the PL-259 not being soldered in all the holes, or something like that.

you mentioned that you don't have anything grounded, and you have a higher powered station. these two things together are a recipe for RF issues.

the MFJ artificial ground thing is a joke. it may make a meter happy, but it's just a band aid on a broken bone.

don't think that just buying a few snap on ferrites is going to fix everything. ferrite may be your answer, but you need to know where to put it, and how much of what mix to use.

you have some work ahead of you once you get that MFJ meter back, and instead of it being the problem, it might be the only thing telling you that you have a problem,

start doing some reading on "RF in the shack" or "rf grounding for amateur radio stations" and things like that. you will pick up a lot of tips, rules and things to try by doing this.

i wish i had an easy answer for you, but like i said, RF problems in your shack can be a beast, and you are the one best equipped to kill the beast, as it lives in your house. LOL

best of luck, please post back once you start troubleshooting everything.
this will be a good place to post your notes as you go along.
LC

 

[Sonar]

the reason i was asking about the mics is because D104's can have a loud "click" to them when you key them, and i was wondering if that was causing the meter to slam the needles.

if you turned your mic gain all the way down, and tried keying up, you would know whether or not this was the problem.


however, after reading your second post, it does seem like a stray RF problem, and sadly, that can be much harder to track down.

the best thing you can do at this point is to do some testing by removing different parts of the station, or changing coax cable lengths between certain items, and noting any changes in performance.

the notes are especially important, because it's all too easy to forget a change that you made.

for example, say you have a six foot coax jumper going from the amp to the antenna switch.
try a three foot jumper here. note any changes, and then change it back to the six foot jumper, and try a different length jumper between the radio and the amp. again,noting any changes.

you have to be methodical about it, and only change one thing at a time, then test, then put it back the way it was, and then change something else.
do this over and over, and you will start to see a pattern in your notes, like, every time this six foot jumper is used after the amp, the meter goes nuts, but when it's used from radio to amp, everything is good.
this would mean that particular jumper may have an RF leakage issue, such as the outer shell of the PL-259 not being soldered in all the holes, or something like that.

you mentioned that you don't have anything grounded, and you have a higher powered station. these two things together are a recipe for RF issues.

the MFJ artificial ground thing is a joke. it may make a meter happy, but it's just a band aid on a broken bone.

don't think that just buying a few snap on ferrites is going to fix everything. ferrite may be your answer, but you need to know where to put it, and how much of what mix to use.

you have some work ahead of you once you get that MFJ meter back, and instead of it being the problem, it might be the only thing telling you that you have a problem,

start doing some reading on "RF in the shack" or "rf grounding for amateur radio stations" and things like that. you will pick up a lot of tips, rules and things to try by doing this.

i wish i had an easy answer for you, but like i said, RF problems in your shack can be a beast, and you are the one best equipped to kill the beast, as it lives in your house. LOL

best of luck, please post back once you start troubleshooting everything.
this will be a good place to post your notes as you go along.
LC

If the problem is stray rf or the dawia two position switch, in your opinion is the one second reading of an off the chart swr really happening or, is it just a phantom reading? If it's just a one second false reading and my equipments in no danger of failing I may in the case I don't find what's causing it and correcting the issue, just leave it as is or, sell the meter for a loss. I do have a dawia true pep (power.supply) reading meter I can use. The reason for my purchase of the MFJ 828 was the frequency counter. I plan on operatating an EF Johnson ranger on AM for local rag chew and the frequency counter makes it so much easier than having to zero beat it every time I change to a different frequency. Thanks again. P.s. I will post the outcome as soon as I get the meter back from MFJ. It was sent out on Friday and I should have it by this coming week..

 

[loosecannon]

sonar, you make a good point. This "needle banging" that goes on with the MFJ doesn't seem to be happening with any other meter you have right?

if one meter does something strange, and no other meters do that strange thing, i would think the one meter that behaves weirdly is the problem.

This is just an opinion, but if only the MFJ meter does this, then it is the thing that needs to go.

heck, the guy at MFJ may know full well that this happens, and feels that it's not "broken" it's just that it was made this way. Maybe an MFJ meter just acts this way and they don't care.

not sure what to think here, but again, if you have a meter that doesn't do it, then just use that meter and DX on IMO.
LC