Stryker modulation in ref to TS 500DX amp.

[Limeybastard]

I set the dead key on the 955 stryker to bare min at first, it was deadkeying the ts500v at just under 100W. But swing was to just 250W or thereof pep. I adjusted the variable on the 955 to get a 100w DK on it now swings to 280W or pep. With 150W deadkey it swings to almost 400 pep.

Am I doing this right? I thought perhaps I had one transistor down from new, so while holding the deadkey I increased the variable on the 955 all the way up and it sure did almost get to 400W deadkey and current draw was about 45AMP so I assume the amp works as it should. I didnt modulate it in this way at all. Was a quick momentarilly test.

What i noticed was with just the radio on, the low deadkey on the Stryker 955 of 4w would swing to 10w pep or 10w swing to 20w pep, this might be the issue with the amp not "swing" the way it should perhaps in relation to 1:4 ratio? I guess what I'm trying to say is the 955 not giving me swing ratio when its on 4 or 5 watts ( swings to 10 or11W) hence why the amp wont swing much either?

Cheers

I have my liquid Ameritron dummy load now here , so I can ran further tests. Just advise. cheers Above figures were prior to dummy load introduction. I can do the above first paragraph tests again via dummy load for better accurate figures.

Currently with dummy load the 955 is the following: Max DK 19W Min DK 4W , Max PEP @ 19W = 50, once it hit 60W i think.

DK 4W swings to 10W pep
DK 10W swings to 22W pep
DK 15W swings to 40W pep
DK 19W swings to 50W pep

 

[tba02]

What meter are you using?

 

[Big Kahuna]

So there were some radios previously (Omegaforce/S9) that were designed to swing to their full output from a low deadkey. On those radios you could key 4 watts and swing 40-50 watts.

Most radios when you lower the deadkey, the total output also decreases.

Your Stryker 955 at max RF power should be hitting 80 watts with modulation unless they've detuned them a bit since I tested it a couple of years ago but you don't want to be swinging that much into the amp.

You don't want a 150W deadkey, I understand you're trying to figure out how to get the most out of the amp but running a high deadkey isn't good long term for your amp.

You radio swing ratio isn't hitting the amp the way you'd like which is part of the issue. If the radio was swinging 30-40 watts from a lower deadkey your amp deadkey could be set lower and you'd still hit 400 watts.

This is a factor of the radio not the amp. Who tuned your 955? Have you had the AMC adjusted?

 

[Mustang 131]

I set the dead key on the 955 stryker to bare min at first, it was deadkeying the ts500v at just under 100W. But swing was to just 250W or thereof pep. I adjusted the variable on the 955 to get a 100w DK on it now swings to 280W or pep. With 150W deadkey it swings to almost 400 pep.

Am I doing this right? I thought perhaps I had one transistor down from new, so while holding the deadkey I increased the variable on the 955 all the way up and it sure did almost get to 400W deadkey and current draw was about 45AMP so I assume the amp works as it should. I didnt modulate it in this way at all. Was a quick momentarilly test.

What i noticed was with just the radio on, the low deadkey on the Stryker 955 of 4w would swing to 10w pep or 10w swing to 20w pep, this might be the issue with the amp not "swing" the way it should perhaps in relation to 1:4 ratio? I guess what I'm trying to say is the 955 not giving me swing ratio when its on 4 or 5 watts ( swings to 10 or11W) hence why the amp wont swing much either?

Cheers

I have my liquid Ameritron dummy load now here , so I can ran further tests. Just advise. cheers Above figures were prior to dummy load introduction. I can do the above first paragraph tests again via dummy load for better accurate figures.

Currently with dummy load the 955 is the following: Max DK 19W Min DK 4W , Max PEP @ 19W = 50, once it hit 60W i think.

DK 4W swings to 10W pep
DK 10W swings to 22W pep
DK 15W swings to 40W pep
DK 19W swings to 50W pep

I would question your peak meter. If its correct your not fully modulating, adjust your mic and amc to around 16 peak from a 4 watt dk.
Personally I would set it for around 2 watts swinging 8-10 watts peak. You'll should get a good clean sound, and your radio and amp should last a long time. You don't need more swang.

 

[543_Dallas]

When the power on the 955 it turned down the carrier and pep power should both drop. The only radios that don't do this have been modified or are like the magnums were with the top gun modulator. This would explain the lower pep power from the amp with the dead key on the radio set lower.

I didn't know if the pep meter was off or the linearity of the amp is that bad. I have little experience with dei transistors. None with tx star amps that use them.

 

[Limeybastard]

What meter are you using?

Swan WM2000A.

 

[Limeybastard]

So there were some radios previously (Omegaforce/S9) that were designed to swing to their full output from a low deadkey. On those radios you could key 4 watts and swing 40-50 watts.

Most radios when you lower the deadkey, the total output also decreases.

Your Stryker 955 at max RF power should be hitting 80 watts with modulation unless they've detuned them a bit since I tested it a couple of years ago but you don't want to be swinging that much into the amp.

You don't want a 150W deadkey, I understand you're trying to figure out how to get the most out of the amp but running a high deadkey isn't good long term for your amp.

You radio swing ratio isn't hitting the amp the way you'd like which is part of the issue. If the radio was swinging 30-40 watts from a lower deadkey your amp deadkey could be set lower and you'd still hit 400 watts.

This is a factor of the radio not the amp. Who tuned your 955? Have you had the AMC adjusted?

I dont really want to get the MAX out of my amp, not at all. I just want to make sure everything is in order. Then I will be running it conservatively. I appreciate your help.

I also believe its the radio, after all what goes in goes out, right? So if its not swinging, then nor would the amp I am thinking.

The 955 is stock untuned or modded, except for the export mod which I did myself, nothing else was changed or adjusted to it from new.

With a deadkey of 100W on the TS500V I cannot swing to more than 250W, just tested it again. So,its either the radio or the meter. Then again, the Texas star meter, can that assist me in isolating it further?

 

[Limeybastard]

I would question your peak meter. If its correct your not fully modulating, adjust your mic and amc to around 16 peak from a 4 watt dk.
Personally I would set it for around 2 watts swinging 8-10 watts peak. You'll should get a good clean sound, and your radio and amp should last a long time. You don't need more swang.

Good point, but Im no going to adjust any pots until I can eliminate the meter in the system as being the cause. I guess, the next question is, do I need to go an buy another pep meter? LOL

 

[Limeybastard]

When the power on the 955 it turned down the carrier and pep power should both drop. The only radios that don't do this have been modified or are like the magnums were with the top gun modulator. This would explain the lower pep power from the amp with the dead key on the radio set lower.

I didn't know if the pep meter was off or the linearity of the amp is that bad. I have little experience with dei transistors. None with tx star amps that use them.

With the power turned down to bare min, the dead key is approx 4W on the Stryker 955. Which swings to approx 10W. PEP on my meter.

On a side note, what are those handwritten 2 digit figures on the transistors? Each of the 4 DEI tranistors has a hand written 2 numericals with the numbers " 58" on them. Is this stating that each of these 4 matched pairs of DEI is rated at 58W ?

Also, the actual meter on the TS500V, what does it show and mean?

 

[Limeybastard]

I would question your peak meter. If its correct your not fully modulating, adjust your mic and amc to around 16 peak from a 4 watt dk.
Personally I would set it for around 2 watts swinging 8-10 watts peak. You'll should get a good clean sound, and your radio and amp should last a long time. You don't need more swang.

Also the meter on TS500V is between 6-8 tops. Whatever that means.

 

[tba02]

The meter you are using is not an active PEP meter and therefore will not show you true PEP - but it is still a useful tool.

** EDIT If the SWAN is a true Active PEP meter then all of this is hogwash**

*Generally* speaking, that type of circuit will show ~70% of true PEP.
That said -
The Dead Key (DK) / PEP numbers you listed are pretty consistently showing ~2.5:1 ratio, which is not unexpected (and not bad/wrong). The 100w DK/PEP numbers you listed also align with the numbers shown w/o the amp engaged. They also represent linearity.

Here are a few theoretical numbers to consider based on information provided;


Unless you have a true active PEP meter all of the above will be relative by a few percent. I wouldn't push a 4xDEI 2879 past 400 watts for regular usage and expect it to last. The only difference between 350 watts vs 500 watts is service life of the amp.

 

[w9cll]

The only difference between 350 watts vs 500 watts is service life of the amp.

Agreed you will never see the difference in actual use

 

[Limeybastard]

The meter you are using is not an active PEP meter and therefore will not show you true PEP - but it is still a useful tool.
*Generally* speaking, that type of circuit will show ~70% of true PEP.
That said -
The Dead Key (DK) / PEP numbers you listed are pretty consistently showing ~2.5:1 ratio, which is not unexpected (and not bad/wrong). The 100w DK/PEP numbers you listed also align with the numbers shown w/o the amp engaged. They also represent linearity.

Here are a few theoretical numbers to consider based on information provided;
View attachment 21451

Unless you have a true active PEP meter all of the above will be relative by a few percent. I wouldn't push a 4xDEI 2879 past 400 watts for regular usage and expect it to last. The only difference between 350 watts vs 500 watts is service life of the amp.

Thanks for the chart, appreciated it. Those were my exact figures. I was under the impression that the Swan wm2000a was a true PEP meter since the toggle switch when turned to PEP mode activates a red bulb , the unit is powered to the 110v wall outlet.

So to to summarize, the readings on the amp are correct for what the Stryker 955 is outputting. However, the swing ratio on the Stryker 955 is not optimal for my application. With optimal I mean 1:4 ratio is not given to me by the radio in the first instance.

When I look at the power meter on the radio and Swan , they look pretty similar. Sometimes the Stryker will hit "correct" modulation ratio ,
I have pulled the amp from the setup and measuring value of the Stryker 955 into a dummy load.

PS i dont think the amp modulated to past 250W on a 100w deadkey, you stated 350W. Each DEI has hand written 58 on them. Assume its there rating?

 

[tba02]

I was under the impression that the Swan wm2000a was a true PEP meter since the toggle switch when turned to PEP mode activates a red bulb , the unit is powered to the 110v wall outlet

I'll be honest, I did a quick look in the internet and did not see that is was an active PEP meter, so I could be wrong.

 

[Limeybastard]

I'll be honest, I did a quick look in the internet and did not see that is was an active PEP meter, so I could be wrong.

Heres the file.