I actually moved the MFJ coax lightning arrestor from its own ground rod to the same ground rod as the antenna mast and the antenna mast ground rod is now connected to the house ground rod about 27 feet away with 4 awg copper wire. When the ground thaws I will be pulling up the now-unused coax lightning arrestor ground rod and relocating it to a spot that will work well with the tower (assuming the tower project gets done).
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How to diagnose and resolve an apparent RF issue in my Anytone AT-5555N II setup
- Thread starter TimmyTheTorch
- Start date
Last night I unboxed the President Mckinley and hooked it up to the PSU. The case for it is also attached to the bonding strip. I did some audio testing using both radios and everything sounded fine on both AM and SSB. I manually moved the antenna coax from one radio to the other. I did find one patch cable with a wonky connector so it was shown the door. I then added in the Diamond Antenna CX-210A coax switch so I could use the two radios with one antenna. According to Diamond, the signal rejection in this switch is good to use it this way. I bonded the switch case to the bonding bar. AM and SSB still sounded fine on both radios. Then I added the MFJ antenna tuner mainly to see what would happen. I bonded its case to the bonding bar. Once again, AM/SSB sounded fine on both radios and SWR was fine. By this point I had become quite annoyed with the location of the mic plug on the Mckinley and with the fussy controls. I'm sure it's fine one you get used to it. My problem is I usually either like something right away or I don't and things don't usually grow on me.
By now I had connected everything except the KL503HD amp, LP filter and power meter. So I bonded the amp case to the bonding bar and connected the amp directly between the Mckinley and antenna. No switch or tuner or Anytone was connected in any way.except through the bonding bar. The Anytone was powered on but nothing was connected to its coax jack. The Mckinley was showing about 5 watts AM output to start so I lowered it to two watts and tested AM. Listening to it via headphones connected to the Anytone it sounded okay on AM at this power level. I played with the modulation level and RF power a bit and was able to keep a clean sounding (if not exactly powerful) AM signal. If I turned the signal up above maybe 3 watts the voice in the Anytone was very fuzzy and hard to understand. That's a far cry from the "up to 30 watts"... Then I switched to SSB and no matter how low I set the RF power on the Mckinley, the output from the amp sounded absolutely horrible. I would not even call it distortion. More like a jumbled, garbled, non-continuous outpouring of verbal garbage. I think it may be safe to say that whatever part(s) of the KL503HD handle the SSB stuff are quite ill at the moment. It's also safe to say that my gamble/attempt to use this amp along with the Q5N2 with its power turned way down was a failure. Another lesson learned by me along life's path.
The last part of my experiment was to try a new KL203P I've had sitting in a box for about 5 months with the Mckinley. It was just radio to amp to antenna and the Kl203P case was bonded. I was able to turn the RF power down enough and set the modulation low enough to have the amp sound clear on both AM and SSB but I'm just not sure that the resulting power output level is worth it.
I am also not certain my new Powermax PM4-120 amp is working properly. I have no specific indication it isn't, I just can't prove it is. I swapped out a PM4-75 with the 120 when the 120 went on a good sale. I may bring the truck battery back downstairs again and re-run a few of my tests to eliminate the PSU as a potential source of the amp problems.
I do want to get the KL503HD fixed up so I can use it with a more appropriate radio but I have no idea where to send it for repairs. I don't want it gutted and steroided up to pump out 1 KW, just reliably working as is it supposed to with with the appropriate input level.
The best part about this process has been learning a whole lot about grounding and bonding that I applied to make my station better and a lot safer.
By now I had connected everything except the KL503HD amp, LP filter and power meter. So I bonded the amp case to the bonding bar and connected the amp directly between the Mckinley and antenna. No switch or tuner or Anytone was connected in any way.except through the bonding bar. The Anytone was powered on but nothing was connected to its coax jack. The Mckinley was showing about 5 watts AM output to start so I lowered it to two watts and tested AM. Listening to it via headphones connected to the Anytone it sounded okay on AM at this power level. I played with the modulation level and RF power a bit and was able to keep a clean sounding (if not exactly powerful) AM signal. If I turned the signal up above maybe 3 watts the voice in the Anytone was very fuzzy and hard to understand. That's a far cry from the "up to 30 watts"... Then I switched to SSB and no matter how low I set the RF power on the Mckinley, the output from the amp sounded absolutely horrible. I would not even call it distortion. More like a jumbled, garbled, non-continuous outpouring of verbal garbage. I think it may be safe to say that whatever part(s) of the KL503HD handle the SSB stuff are quite ill at the moment. It's also safe to say that my gamble/attempt to use this amp along with the Q5N2 with its power turned way down was a failure. Another lesson learned by me along life's path.
The last part of my experiment was to try a new KL203P I've had sitting in a box for about 5 months with the Mckinley. It was just radio to amp to antenna and the Kl203P case was bonded. I was able to turn the RF power down enough and set the modulation low enough to have the amp sound clear on both AM and SSB but I'm just not sure that the resulting power output level is worth it.
I am also not certain my new Powermax PM4-120 amp is working properly. I have no specific indication it isn't, I just can't prove it is. I swapped out a PM4-75 with the 120 when the 120 went on a good sale. I may bring the truck battery back downstairs again and re-run a few of my tests to eliminate the PSU as a potential source of the amp problems.
I do want to get the KL503HD fixed up so I can use it with a more appropriate radio but I have no idea where to send it for repairs. I don't want it gutted and steroided up to pump out 1 KW, just reliably working as is it supposed to with with the appropriate input level.
The best part about this process has been learning a whole lot about grounding and bonding that I applied to make my station better and a lot safer.
Good to see you making progress. A McKinley should be a great match with a 203P. It's a waste of time (and a recipe for disaster) with a Q5Nii however.
I still question how reliably your power supply is working... It might be unrelated, but whenever your current draw increases, so does the problem (it would seem).
I would still like to see all of this testing done with a reliable power supply, such as a car battery (before you assume the amps are faulty).
Good luck!
Well, so far this has been fun. I've been searching about to see where one RM4 and 8 RM3 MOSFETs are available and determine if I think I will try this replacement myself.
I've seen the RM3 said to be IRF520, IRF9530, 2N6045, HUF75345P3, FQP13N10 and more. Doesn't matter. So far I'm shooting blanks at finding anywhere on this continent that have any.
Then I try the RM4. I read that the part number is removed from the part before it leaves RM. Well, okay then. I've read the RM4 is really the same part as the RM3, only called differently on the schematic to distinguish between driver and driven. True? Who knows. I've not yet found any actually individual part number for the RM4.
I also see a lot of various information about needing to make additional adjustments to voltages and biases to properly tune the replacement mosfets to work with the rest of the electronics. True? Who knows.
Every industry sure does love their secrets. Good thing I'm curious by nature. And determined (although my wife spins it as stubborn).
I'm going to do the car battery test over lunchtime. The battery is now inside warming up a bit first. Truck batteries are heavy!
I've seen the RM3 said to be IRF520, IRF9530, 2N6045, HUF75345P3, FQP13N10 and more. Doesn't matter. So far I'm shooting blanks at finding anywhere on this continent that have any.
Then I try the RM4. I read that the part number is removed from the part before it leaves RM. Well, okay then. I've read the RM4 is really the same part as the RM3, only called differently on the schematic to distinguish between driver and driven. True? Who knows. I've not yet found any actually individual part number for the RM4.
I also see a lot of various information about needing to make additional adjustments to voltages and biases to properly tune the replacement mosfets to work with the rest of the electronics. True? Who knows.
Every industry sure does love their secrets. Good thing I'm curious by nature. And determined (although my wife spins it as stubborn).
I'm going to do the car battery test over lunchtime. The battery is now inside warming up a bit first. Truck batteries are heavy!
I got FQP13n10s here:
Lot of Genuine ONSEMI FQP13N10 MOSFET Transistors USA Seller RF Final | eBay
These are not Chinese counterfeit fakes! Beware of those sold on this platform!
www.ebay.com
Thanks for the link. Is the same one used for RM4 as well?I got FQP13n10s here:
Lot of Genuine ONSEMI FQP13N10 MOSFET Transistors USA Seller RF Final | eBay
These are not Chinese counterfeit fakes! Beware of those sold on this platform!www.ebay.com
I used 3 to replace the driver and finals in my Q5n. It still does 35w.
I have no idea. Haven't had the Q5n2 open since clipping the wire inside, take some pics, and jump the jumper. I'm keeping that radio for the truck.
I was actually referring to the KL503HD, not the Q5N2. I should not have asked that in this thread. I have another thread going in the Amplifiers area and will try to restrict this type of question there. This thread just kind-of meandered along with what specific point of troubleshooting I was at in my station issue.
The good news is that my Q5N2 seems to be working 100 percent, no issues with it at all. During this exercise I did find one flaky RG8X patch cable and got my gear hopefully properly grounded and bonded.
Here is a stocking source for IRF520's.
73
David
73
David
For now, just use the lightning arrestor ground rod. Run a 4 or 6 gauge to it from the mast grounding rod. You can never have too much ground as long as they are all connected. Later, when things thaw, you can pull it up if you want.
That's all I do. Antenna, arrestor to ground rod, coax into the shack, swr/pwr, amp, radio.
All the electronics are grounded through the coax shield, and the pwr supply. I have never had to run separate grounds to equipment.
its amazing how much wrong information gets thrown around in the cb radio community, all because people dont want to find the correct answer via research. ridiculous.