XPR5550 external spkr

[jerryray]

I tried using pins 9&10 for external speaker to my mixer.
I get a terrible dc pop at the end of each transmission. I tried a bypass ca and a 1:1 isolation transformer.
Anyone else encounter and solve this problem?

TIA
K2JRC

 

[com501]

You can't do that. There is a DC potential on each side of the speaker lead.

What mixer? The output of the radio is 4-8 ohms at several watts. You would need to severely limit the input to your mixer on the secondary side of your transformer. You cannot ground either side of the speaker output or common it.

 

[jerryray]

Thanks for the reply, I tried a 8 ohm speaker, that pops as well. I can try to dc isolate each side, Strange that a real external speaker does it too. What impedance are the Motorola external speakers?

JC

 

[N4KVE]

When I briefly had a UHF 5550, I too noticed that pop at the end of each transmission. But using that same cable & speaker on both my 4550's produced no pop. One reason I got rid of the 5550. People may call me crazy, but I prefer the 4550 to the 5550.

 

[jerryray]

Well, I used a bypass cap on each leg into a balanced line input and still heard the pop.

 

[jerryray]

So after investigating this further, it seems the speaker out is not for YOUR speaker, it's for the Motorola Powered speaker, 3 choices out there. I ordered the RSN4002A 13 watt version. If it does not pop, I will build in a speaker or aux balanced out with transformer isolation.

So be careful, this XPR5500 is no like the old Maxtracs

 

[firefive76]

We have multiple XPR5550's running external speakers and have not had any of the "pop" problems. They are not powered external speakers either.

 

[jerryray]

Really, what is the DC impedance what pins have you connected to?
Thanks

 

[N4KVE]

13 watt speakers are just 3 1/2 ohms instead of 8 ohms, so with less resistance, they sound louder. But because they sound louder, they charge quite a bit more for them, even though they cost the same to make. Talk about easy money. LOL.

 

[jerryray]

So you don't think there is any active amp. The radio is only rated for 3 watts Audio out. I assumed a 13 watt speaker is amplified.
Do you see 13 volts across the speaker output pins 9@10 ?
I don't see any options in CPS for speaker out routing.

Thanks

 

[N4KVE]

I don't see any options in CPS for speaker out routing.

Thanks

There isn't any. When I got my 1st 4550, I too was concerned with the radio running 2 speakers at the same time, as my old Maxtrac wasn't happy doing that years ago. I was assured that it's not bad for the radio to do this, as the large external speaker will be so loud, I won't even hear the small internal speaker. It sounded great, but when I had a 5550 for a month [a friend needed $ so he pawned it to me until he could buy it back] I connected the same external speaker to the 5550 that had been on the 4550, & immediately noticed the popping noise when the carrier dropped. Plugged the speaker back into the 4550, & no popping noise. I mentioned this thread to my friend, & he does not hear a popping noise, but he doesn't use an external speaker. Also, his radio sits in a noisy work van, but when I owned it, the radio sat in a quiet house.

 

[ramal121]

I tried using pins 9&10 for external speaker to my mixer.

My question is if you are trying to feed a mixer why you are not using pin 14 Rx Audio and pin 12 Gnd???

 

[jerryray]

Is pin 14 muted audio?

I'll try it, any dc that needs to be blocked?

 

[jerryray]

Works great, did not know audio was at that pin.

 

[jerryray]

The only problem I have is there is a channel free tone, which is adjustable through the CPS software, it works as I set it (-20db) from the speaker, but from this audio pin 14 source the beep is very loud. So in the end I may still have to modify the speaker when I get it.
The channel free tone is like a repeater tail tone. Without it you don't know the other person has actually dropped the carrier.

 

[jerryray]

Just an FYI, I did get the 13w Speaker and it is NOT active. In the car I can't hear the pop when the audio gate opens, but at home I sure do.

Does this pop bother anyone else using the external speaker at home?

Cheers

 

[N4KVE]

Yeah me, one of the reasons I sold the radio, & went back to the 4550 which does not pop.

 

[jerryray]

For all that may have the same problem in the shack. I cut one of the speaker wires added a DPDT Center off switch with a 22 ohm resistor across the two ends. Center= No external speaker, one direction lower level about equal to the internal speaker, less clicking. Other direction is normal straight through.

Works..