Galaxy dx99v replacement meter bounce

[Cable Guy]

Hi, I replaced a siezed meter in above radio, replacement ordered from a place I often order from, I noticed the movement is very bouncy. While on ssb rx, of course the needle is gonna move quite a bit, but this one bounces back with a vengeance although not enough to smack the left edge. On am, when observing a carrier from a local station, the meter whips way past its expected s-unit mark and bounces around +/- 3 s-units for a few seconds until it settles on the actual reading. Seems like there needs to be some dampening. Think I got a bad meter?

 

[loosecannon]

no they are just like this these days.

While im happy that people are having meters made that fit our radios, i do wish they were a bit better made.

Ive seen this with replacement 2000GTL meters, 142GTL style meters, as well as the galaxy and ranger meters.
LC

 

[brandon7861]

Can you dampen it with a small disk capacitor?

This meter came out of a motorola watt meter someone gave me. It has a cap. This meter is 100uA full deflection so if yours is the same FSD,, the same cap would probably work good. The cheaper things get, the lighter they get, so the same amount of current will move it faster.

 

[Cable Guy]

Can you dampen it with a small disk capacitor?

This meter came out of a motorola watt meter someone gave me. It has a cap. This meter is 100uA full deflection so if yours is the same FSD,, the same cap would probably work good. The cheaper things get, the lighter they get, so the same amount of current will move it faster.
View attachment 72651View attachment 72652

I will try a few values, I'm not sure the full scale deflection current of this meter but some measurements could clear that up, then I could figure the time constant and determine the cap value needed, I know I could use the exercise, but I'll just try a few. Thanks Brandon.

 

[Eldorado828]

I will try a few values, I'm not sure the full scale deflection current of this meter but some measurements could clear that up, then I could figure the time constant and determine the cap value needed, I know I could use the exercise, but I'll just try a few. Thanks Brandon.

Let us know what you come up with, @brandon7861 is on to something. Your results could be a great help to the rest of us who might find ourselves in the same dilemma.

 

[nomadradio]

Can you dampen it with a small disk capacitor?

More likely an electrolytic around 10uf. A ceramic disk serves only to bypass RF current. A typical thing to do in a wattmeter.

73

 

[Cable Guy]

More likely an electrolytic around 10uf. A ceramic disk serves only to bypass RF current. A typical thing to do in a wattmeter.

73

That's kinda what I was thinking, maybe even higher than 10uf. A common .01 wouldn't even begin to dampen.

 

[Cable Guy]

Done, I didn't see any debounce below 220uf. I found a 470uf really smoothed it out to what I wanted. Not whippy anymore, no overshoot, no zero stop slap and no excessive hang. The small value current shunt resistor across the coil requires a much larger capacitor value to achieve the needed r/c time constant. Ymmv.