Toggle sidebar Toggle sidebar
  • You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • A Winner has been selected for the 2025 Radioddity Cyber Monday giveaway! Click Here to see who won!

Var. RMS?

Hawkeye351

Hawkeye351

Sr. Member
Jun 27, 2021
786
747
103
58
Got a question...

There's a local around here that speaks often about his radio having two separate controls mounted on the back of his radio. He states one is to vary is RMS, while the other varies his Peak. He had it done by a well known radio guy down south of me (very well known in the radio community).

My question is, what's the purpose of variable RMS?
 
  • Like
Reactions: Naysayer and Shadetree Mechanic

I believe having variable RMS allows the user to maximize the output of an amplifier. Or maybe wring every last watt out of it, is what it makes me think.

One time I hooked up a kl203 amp to a ten amp power supply that had a transformer in it. I couldn't hit 100 watts peak, so I put it on a twenty amp switch mode supply and got 120 watts peak. But the average power was the same. So I was surprised that the power supply affected only the peak. Maybe the knob on the radio does something along those lines to get adjustable RMS?
 
  • Like
Reactions: Hawkeye351
Hawkeye351 said:
Got a question...

There's a local around here that speaks often about his radio having two separate controls mounted on the back of his radio. He states one is to vary is RMS, while the other varies his Peak. He had it done by a well known radio guy down south of me (very well known in the radio community).

My question is, what's the purpose of variable RMS?
Click to expand...
I wondered that too and I look forward to a good Answer. You're writing about the Striker radio, right? The mod adds 2 controls to the radio, I saw several YT vids on it. Seemed like a standard mod the shop does.
 
  • Like
Reactions: Hawkeye351
Shadetree Mechanic said:
I believe having variable RMS allows the user to maximize the output of an amplifier. Or maybe wring every last watt out of it, is what it makes me think.

One time I hooked up a kl203 amp to a ten amp power supply that had a transformer in it. I couldn't hit 100 watts peak, so I put it on a twenty amp switch mode supply and got 120 watts peak. But the average power was the same. So I was surprised that the power supply affected only the peak. Maybe the knob on the radio does something along those lines to get adjustable RMS?
Click to expand...

The amp could not produce full peak power on the ten amp supply. It was being starved for current. Running it off the 20 amp supply allowed it to pull full peak current, whereas the ten amp supply would only allow a much lower power. The amp neither knows nor cares whether that power is average nor peak. No such thing as RMS power BTW despite it being universally used. When people refer to "RMS power," they are actually using a misnomer for average power.)
 
  • Like
Reactions: Shadetree Mechanic, BC Coyote and Hawkeye351
Naysayer said:
I wondered that too and I look forward to a good Answer. You're writing about the Striker radio, right? The mod adds 2 controls to the radio, I saw several YT vids on it. Seemed like a standard mod the shop does.
Click to expand...

Yes it is a Stryker, 497 I believe.
This guy that owns the radio works on tube amps, very good at it too. He sends all his radios off down south of NC to that well known radio guy.

He specifically stated one is for adjustable peak and the other for adjustable rms. He already has an adjustable carrier (key) control, so it's not that.

What are the advantages/disadvantages of variable peak and variable rms? Are they an improvement or just another fad?
 
Hawkeye351 said:
just another fad?
Click to expand...
Until I see a schematic that's all they are. Just another flavor of secret sauce. Ideally the radio's RMS power at full modulation should be the same regardless of carrier setting. It's all about the waveform. If you smoosh the positive peaks this raises the average power but hoses your audio quality.

Wattmeter worshipping is a fad that will never go away.

73
 
  • Like
Reactions: Hawkeye351 and Shadetree Mechanic
I will say this about it:

He praises this guy down south, as many other people do. He paid over 1200 bucks to have those two controls, HiFi, recorder and noise toys added.

Funniest thing about it all is the fact that my work on these 30 to 50 year old radios that people are giving up on is stronger on signal and audio than his 1200 dollar toy. My radios don't need variable RMS to drive the snot out of an amp. Oh, and he basically has to run an amp with it all the time, many of my radios do a great job barefoot.

He does complain about locals co-channeling, but my friends always tell him their radios (my work) doesn't catch as much bleed over as he complains about. I told him it's a shame he spent all that money on his transmit which really didn't help his signal but also he didn't invest a dime in his receive to limit co-channeling.

Like I always say, if it doesn't help/improve the transmit, then it's worthless to me. I'm about getting out there, not toys.
 
  • Like
Reactions: Shadetree Mechanic and TM86

dxChat
Help Users
  • No one is chatting at the moment.


      Top Bottom