PROPERLY TUNING A PALOMAR 350Z

[Sonar]

As per 350Z manual tunning procedure.
Must begin tuning in the low power position.
Tune Driver plate and final plate during a single key down for maximum smoke. Unkey then tune load for max smoke.
Once that's done several times and the amp is tuned for Max smoke it's good to go in the low side.

In order use the amp in the high side switch to that position (hight.)
Then make slight adjustments to the driver plate, final plate, and load (in that order) for max smoke.
Repeat until Max smoke is obtained.

My question is after going through this procedure (to operate high side) the amplifier is showing 500 watts dead key.
NO NEED TO OVER COUPLE THE DRIVER PLATE OR LOAD AS IN THE 300A?
If I follow the manual directions there's absolutely little to no pep when modulation is added.

I've been over coupling the driver plate clockwise in order to drop the dead key down to approximately 175 watts, and see 500 pep with great audio reports.

Unlike the directions for for Palomar 300a over coupling is necessary in order to drop the dead key down for Forward pep.
If this is not done (Advanced load on the 300 a) crappy crunchy audio is inevitable.

Both amps show almost exactly the same output when tuned for Max smoke (before over coupling)

Did they (Palomar) just leave the fact that you have to over couple a 350Z out of the manual?

Or is this the way one is supposed to run a 350Z?
Am I going to cause irreparable damage by over coupling the driver plate when that not the manuals tuning procedure?

When I first took the 350Z out of the box it's been sitting in for quite some time it had written directions (by the original owner) that stated after tuning for Max smoke in the high side advance the driver plate clockwise in order to drop down the dead key carrier (over coupling correct?)

I recently downloaded the 350Z manual and the tuning directions are different than that of the original owners written ones. And surprise me at the lack of mentioning over coupling.

I'm assuming Palomar left out the fact that the amp has to be over coupled.
But I'm wondering if I'm using the wrong control to do so.
Should I be advancing the load control on the 350Z as opposed to the driver plate?
Should I be following the printed Palomar 350Z tuning directions and tune for max smoke without over coupling or follow the original owners written directions for tuning?

I just hope I'm using the correct control to over couple. I'm also concerned albeit just a little bit that I actually shouldn't be over coupling as per palomares manual.

 

[dozerman]

As per 350Z manual tunning procedure.
Must begin tuning in the low power position.
Tune Driver plate and final plate during a single key down for maximum smoke. Unkey then tune load for max smoke.
Once that's done several times and the amp is tuned for Max smoke it's good to go in the low side.

In order use the amp in the high side switch to that position (hight.)
Then make slight adjustments to the driver plate, final plate, and load (in that order) for max smoke.
Repeat until Max smoke is obtained.

My question is after going through this procedure (to operate high side) the amplifier is showing 500 watts dead key.
NO NEED TO OVER COUPLE THE DRIVER PLATE OR LOAD AS IN THE 300A?
If I follow the manual directions there's absolutely little to no pep when modulation is added.

I've been over coupling the driver plate clockwise in order to drop the dead key down to approximately 175 watts, and see 500 pep with great audio reports.

Unlike the directions for for Palomar 300a over coupling is necessary in order to drop the dead key down for Forward pep.
If this is not done (Advanced load on the 300 a) crappy crunchy audio is inevitable.

Both amps show almost exactly the same output when tuned for Max smoke (before over coupling)

Did they (Palomar) just leave the fact that you have to over couple a 350Z out of the manual?

Or is this the way one is supposed to run a 350Z?
Am I going to cause irreparable damage by over coupling the driver plate when that not the manuals tuning procedure?

When I first took the 350Z out of the box it's been sitting in for quite some time it had written directions (by the original owner) that stated after tuning for Max smoke in the high side advance the driver plate clockwise in order to drop down the dead key carrier (over coupling correct?)

I recently downloaded the 350Z manual and the tuning directions are different than that of the original owners written ones. And surprise me at the lack of mentioning over coupling.

I'm assuming Palomar left out the fact that the amp has to be over coupled.
But I'm wondering if I'm using the wrong control to do so.
Should I be advancing the load control on the 350Z as opposed to the driver plate?
Should I be following the printed Palomar 350Z tuning directions and tune for max smoke without over coupling or follow the original owners written directions for tuning?

I just hope I'm using the correct control to over couple. I'm also concerned albeit just a little bit that I actually shouldn't be over coupling as per palomares manual.

What kind of drive are you putting into it to get a 500 watt dk? I know it's a different amp, but my 300a, I was seeing a 350 watt dk with a 3 watt key. I turned it down inside. The trimmer under the driver board. I backed it off until I had a 250 watt key at max smoke. I used the instructions for the 300a, which are the same for the 350 I assume.

Before, I had a 350 dk and swing of 150. That's it. After backing it down it's much better. I can dk 250 and load clockwise under audio to 700 plus. I can get 50 or more by tuning counter clockwise just a touch. According to locals and gates, it is crystal clear and LOUD. i made one of my cobra 1000's mosfet and variable power to run it. I tune it at 4 watts, then back it down to a watt. Keys about 125 and swings 700 plus. I put 6 NOS 6lf6's in it. Does better than the kd6's, in my case anyway.

 

[543_Dallas]

Over coupling is when the load capacitor is unmeshed too far (not enough capacitance) and undercoupled is when it is meshed too far (too much capacitance). Under coupling causes high grid current and can cause arcing. Over coupling reduces grid current but raises plate current. If you're going to mistune an amp it's better to overcouple.

I tune up an amplifier for max smoke with an unmodulated carrier equal to or slightly above the pep power the amp will be driven with during normal use. When tuning for the first time start out with low power and work your way up. Do it quickly and make sure the grid and plate current aren't excessive. When youre done reduce drive and leave it alone. All the usual whistling or yelling into the mic to tune up is unnecessary.

 

[Sonar]

What kind of drive are you putting into it to get a 500 watt dk? I know it's a different amp, but my 300a, I was seeing a 350 watt dk with a 3 watt key. I turned it down inside. The trimmer under the driver board. I backed it off until I had a 250 watt key at max smoke. I used the instructions for the 300a, which are the same for the 350 I assume.

Before, I had a 350 dk and swing of 150. That's it. After backing it down it's much better. I can dk 250 and load clockwise under audio to 700 plus. I can get 50 or more by tuning counter clockwise just a touch. According to locals and gates, it is crystal clear and LOUD. i made one of my cobra 1000's mosfet and variable power to run it. I tune it at 4 watts, then back it down to a watt. Keys about 125 and swings 700 plus. I put 6 NOS 6lf6's in it. Does better than the kd6's, in my case anyway.

I'm driving it with a sonar FS 2340 at one and a half Watts dead key pep is 15-17.
With the mic gain on the Demco modulator turned all the way down I go back and forth from drive to load until Max smoke is reached, and then take care of the the final knob on the rear of the amplifier for Max smoke.
Once that's done the 300 a shows 450 (actually a bit over that.)
Are you then turns the load knob clockwise until the 450 dead tea drops to approximately 150 watts.
Without over coupling it in order to drop the dead key carrier down there is no swing and the modulation reports are horrible.
As far as going inside the amplifier and turning anything down I'm not familiar with that although it does actually mention something similar to that on the manual for the 350Z.
It's the 350Z and it's tuning instructions provided by Palomar that are a bit confusing.
After tuning up the 350Z as per its manual there's a dead key of 500 watts.
On a.m. Which is where I'm currently using the 350Z just like the 300a before over coupling (turning the load control clockwise a contactor) drops the dead key carry it down, cleans up the audio.
As far as the 350Z manual there's no mention of over coupling. How do they expect an owner of that amplifier to modulate with a 500 watt dead key?
Unless the carrier is drop down there's no forward modulation, and the audio reports are horrible. Crunchy, raspy, over driven are the reports I got before I turn the driver plate knob counterclockwise until the dead key shows approximately 150. When that's done I show 500 watts p e p excellent audio reports.
My concern is that I may be taking the amplifier out of resonance by doing this. But without doing it the amplifier is worthless as it makes the audio sound horrible.
As I mentioned with the 300 a as per manual instructions from Palomar advancing the load knob clockwise a bit in order to drop the dead key carrier will clean the audio up and show forward modulation. It works great when the load knob on the 300a is Advanced clockwise. And that's exactly what the 300 a Palomar manual suggest. The Only Exception is when the amp is being used on SSB. No need for over coupling in order to drop the carrier when using us it's on sideband. PS. I I'm not sure why you're surprised at the 500 watt dead key. That's what 2 6lf6's driving 4 6lf6's should be.
700 Watts sounds like you may be over driving.
The tubes aren't rated in totality for that type of output. It's approximately 250 W Moore then it should be showing.

 

[dozerman]

I'm driving it with a sonar FS 2340 at one and a half Watts dead key pep is 15-17.
With the mic gain on the Demco modulator turned all the way down I go back and forth from drive to load until Max smoke is reached, and then take care of the the final knob on the rear of the amplifier for Max smoke.
Once that's done the 300 a shows 450 (actually a bit over that.)
Are you then turns the load knob clockwise until the 450 dead tea drops to approximately 150 watts.
Without over coupling it in order to drop the dead key carrier down there is no swing and the modulation reports are horrible.
As far as going inside the amplifier and turning anything down I'm not familiar with that although it does actually mention something similar to that on the manual for the 350Z.
It's the 350Z and it's tuning instructions provided by Palomar that are a bit confusing.
After tuning up the 350Z as per its manual there's a dead key of 500 watts.
On a.m. Which is where I'm currently using the 350Z just like the 300a before over coupling (turning the load control clockwise a contactor) drops the dead key carry it down, cleans up the audio.
As far as the 350Z manual there's no mention of over coupling. How do they expect an owner of that amplifier to modulate with a 500 watt dead key?
Unless the carrier is drop down there's no forward modulation, and the audio reports are horrible. Crunchy, raspy, over driven are the reports I got before I turn the driver plate knob counterclockwise until the dead key shows approximately 150. When that's done I show 500 watts p e p excellent audio reports.
My concern is that I may be taking the amplifier out of resonance by doing this. But without doing it the amplifier is worthless as it makes the audio sound horrible.
As I mentioned with the 300 a as per manual instructions from Palomar advancing the load knob clockwise a bit in order to drop the dead key carrier will clean the audio up and show forward modulation. It works great when the load knob on the 300a is Advanced clockwise. And that's exactly what the 300 a Palomar manual suggest. The Only Exception is when the amp is being used on SSB. No need for over coupling in order to drop the carrier when using us it's on sideband. PS. I I'm not sure why you're surprised at the 500 watt dead key. That's what 2 6lf6's driving 4 6lf6's should be.
700 Watts sounds like you may be over driving.
The tubes aren't rated in totality for that type of output. It's approximately 250 W Moore then it should be showing.

I drive it with a cobra 1000 with variable power. Keys from 1 to 6 watts swinging to 19-22 pep. I've got another 1000 I've made mosfet that swing about 35 pep that really makes it swing. I know before turning it down inside, mine was the same way. 400 watt plus dead key swinging 600-ish. When I tune it, I keep it at 4 watts then back it down to 1watt after tuning. Everyone says it sounds good. Audio is clear and not pinched like you would expect from over driving. I may be selling it before long. I picked up a Maco 200, 300 and 750 today. CB stands for "constantly buying". I'm sure of it

 

[Sonar]

I drive it with a cobra 1000 with variable power. Keys from 1 to 6 watts swinging to 19-22 pep. I've got another 1000 I've made mosfet that swing about 35 pep that really makes it swing. I know before turning it down inside, mine was the same way. 400 watt plus dead key swinging 600-ish. When I tune it, I keep it at 4 watts then back it down to 1watt after tuning. Everyone says it sounds good. Audio is clear and not pinched like you would expect from over driving. I may be selling it before long. I picked up a Maco 200, 300 and 750 today. CB stands for "constantly buying". I'm sure of it

I'm not positive, but tunning up an amplifier with 4 watts then changing the driver by lowering it to 1 watt after the amplifier was tuned with a higher drive might leave the amplifier running out of resonance.
I too used to do the exact same thing using the variable output knob on my Uniden Madison. I actually posted the question as to whether tuning up and amplifier (300 a) with a certain amount of drive, and then dropping that drive down after tuning up the amplifier with a higher drive would affect the amplifiers resonance. I don't recall the replies I got to that question but I do remember not doing that any longer after reading those replies. When I was using the 300 a I would tune it up with 11/2 Watts from the get-go, and just ran the amplifier at the same output at which I tuned it up with. 73's ps. I'm not sure if there is a way you can use this site search engine in order to find the original posting, but if you can it might be an interesting read as there were many replies from very knowledgeable members.

 

[dozerman]

I'm not positive, but tunning up an amplifier with 4 watts then changing the driver by lowering it to 1 watt after the amplifier was tuned with a higher drive might leave the amplifier running out of resonance.
I too used to do the exact same thing using the variable output knob on my Uniden Madison. I actually posted the question as to whether tuning up and amplifier (300 a) with a certain amount of drive, and then dropping that drive down after tuning up the amplifier with a higher drive would affect the amplifiers resonance. I don't recall the replies I got to that question but I do remember not doing that any longer after reading those replies. When I was using the 300 a I would tune it up with 11/2 Watts from the get-go, and just ran the amplifier at the same output at which I tuned it up with. 73's ps. I'm not sure if there is a way you can use this site search engine in order to find the original posting, but if you can it might be an interesting read as there were many replies from very knowledgeable members.

I will do that for sure! it's a great little amp and don't want to ruin it, but it seems to work well like that. The local dx, 75+ miles all say it has great swing like that so I keep doing it. But I will try to find that original post for sure. Thanks for the heads up

 

[Sonar]

Update on tuning my 350Z. Driver plate k(third knob.)
Final plate (first knob.)
Then load (center knob.)
All for max smoke (ouput.)
Repeating this about 3 times should put the amp at Max output.
Final adjustment is to advance the load (middle knob) clockwise just a bit to drop the dead key carrier.
With one and a half watt dead key drops the carrier from almost 500 watts dead key to about 125.
With 15 watts pep the amp runs exactly like this.
125 dead key 500 pep.
This is what I believe to be the correct way to tune a Palomar 350z.
It runs cool. Great reports.
I believe this is the correct way to tune this particular amp. I hope so. I would hate to think I'm running the amp out of residence.
It runs so nicely with the above description of how I tune it.
If I'm doing it wrong and anyone knows that for fact please let me know. I would appreciate it 73 s

 

[Sonar]

Update on my 300a. Had the mfj 1500 watt dummy load hooked up and was using my Autek wm 1 to tune the amp.
For some reason the high swr light on the Madison lite.
The 300a's rf deck fuse blew. The time between I keyed and un keyed the mic was an eye blink. I replaced the fuse and the amp fired up. I switched from the dummy load to the antenna.
I keyed the Madison with the amp in stby.
set the variable on the Madison to 11/2 watts. Keyed the mic and the swr was 1.1:1. Obviously the high swr light on the Madison was not lit. 12 watts of audio. All good. Unfortunately when I took the Madison out of stby the lights in the shack dimmed and ilooked like the aurora borealis coming from underneath the amplifier near the driver tubes. The high SWR when the amplifier was keyed while the dummy load was in line obviously caused what I assume is some serious damage. I'm not even sure if I'm going to send it out for repair. I might just retire it. It still has its two 6KV6 + 4 6lf6's witch I'm assuming still in good shape considering I was getting nearly 475 watts out of that amplifier. I do believe I own another amplifier that uses 6 LF 6 tubes. So having them for backups I guess isn't so bad considering the high prices they're getting for them. I'm up in the air on whether I'm going to have it repaired or not. As of now I'm using another amp in it's place. I have decided to switch over to transistorized amplifiers. I am most likely going to go with the Texas Star 500v. These old sweep tube amplifiers are wonderful to operate, nice to look at, but when they need to be repaired it's very dangerous shipping them. I know that most likely the same thing would have happened to a Texas Star had it been hooked up at that particular time. But packing it up for shipping leads me to believe it will reach its destination just as it left here and we'll make it back the same way. Between the age of the tube amplifiers and the fact that there's glass involved always leaves me biting my nails between the time I send one of them out and receive it back. I've never had any of them broken during shipping but I truly believe it's only a matter of time. I never did find out what exactly happened to cause the SWR to be Sky High but I'm assuming it might be the mfj dummy load. I will no longer be using that. There's also a small possibility it may have been my wm1. I had recently tightened up the nut that holds the pl-259 on the wm1'S remote head. The pl-259 was loose and the spinning slightly to the right and left possible tightening the nut may have caused the Center and negative Wirers that are attached to the pl-259 to come together. I will be sending that out to a friend of mine in order to have him open up the remote head and take a look at it. Until then I am using my backup wm1. Not having much luck lately with my station. I've decided 2 remove my coax from the antenna and replace both pl259 on either end. Ever since a severe storm and single-digit Temps I've had high swr issues and even though I removed 3ft of my lmr400 and replace the pl-259 the issues are still popping up. When I first replaced the pl-259 that leads to the antenna my SWR was a perfect 1.1:1. After the next rainstorm it rose up to above 2. My sonar 2340 is having an audio issue. I purchased a 12at7 driver and two 6bQ5's, I will be replacing them when I receive them on Monday. I'm hoping that's the issue causing my pep to drop from 12 to 4 watts after about 15 minutes of using the radio. When shit happens it really happens big time. At least that's the luck that I have. 73's