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Accessory SP-31 speaker - Filters ?

 

I crossposted this to a Kenwood Facebook group but need to cast a wider net for answers. I recently got a Kenwood SP-31 speaker (off eBay) to match with my nice TS-870. I plugged it in and the speaker itself seems fine. I downloaded the manual and read it, then started experimenting with the built in audio filters. But I can hear no evidence that they work, at all. This is disappointing and disturbing but before I ask the seller for a refund, wanted to see if someone here has experience and guidance.

I push the three buttons in all the various possible combinations, but there is essentially no change in the audio. I found _three_ different CW signals close to each other, spread in tone from quite low to medium to high, and tried the filters. No change that I could tell, none were attenuated in the least. Same with SSB, no change in tone or noise or attentuation of nearby signals.

Is this thing broken, or is there something else I need to know, my expectations somewhere off reality? Can it be repaired or improved?

Thanks,
Charlie, WB4FAW
 

Charlie,
I don't have that exact speaker but I do have each of SP-180 and SP230. Both have the three filter buttons. On SSB there's a big difference between the three.
On CW it's hard to tell the difference but the difference you hear on cw is the background noise. They don't really do anything for narrowing down cw.
73, Bob? W4JFA

On Sat, Feb 18, 2023 at 5:29 PM Charlie Fellenbaum - WB4FAW <charlie@...> wrote:
I crossposted this to a Kenwood Facebook group but need to cast a wider net for answers. I recently got a Kenwood SP-31 speaker (off eBay) to match with my nice TS-870. I plugged it in and the speaker itself seems fine. I downloaded the manual and read it, then started experimenting with the built in audio filters. But I can hear no evidence that they work, at all. This is disappointing and disturbing but before I ask the seller for a refund, wanted to see if someone here has experience and guidance.

I push the three buttons in all the various possible combinations, but there is essentially no change in the audio. I found _three_ different CW signals close to each other, spread in tone from quite low to medium to high, and tried the filters. No change that I could tell, none were attenuated in the least. Same with SSB, no change in tone or noise or attentuation of nearby signals.

Is this thing broken, or is there something else I need to know, my expectations somewhere off reality? Can it be repaired or improved?

Thanks,
Charlie, WB4FAW

 

Hi Bob,
Thank for the quick reply.
So if the speaker I have does not do anything on SSB either, is it fair to say that this unit is suspect/needs work?
I'll focus testing on SSB over the next day or so.
73,
Charlie
 

Unless your hearing is bad I think there should be no doubt that it either works or doesn't.
Bob

On Sat, Feb 18, 2023, 6:53 PM Charlie Fellenbaum - WB4FAW <charlie@...> wrote:
Hi Bob,
Thank for the quick reply.
So if the speaker I have does not do anything on SSB either, is it fair to say that this unit is suspect/needs work?
I'll focus testing on SSB over the next day or so.
73,
Charlie

 

I checked the schematics. The filters are the same in all three speakers, sp31 sp230, sp180.


On Sat, Feb 18, 2023, 7:00 PM Bob via <W4JFABob=[email protected]> wrote:
Unless your hearing is bad I think there should be no doubt that it either works or doesn't.
Bob

On Sat, Feb 18, 2023, 6:53 PM Charlie Fellenbaum - WB4FAW <charlie@...> wrote:
Hi Bob,
Thank for the quick reply.
So if the speaker I have does not do anything on SSB either, is it fair to say that this unit is suspect/needs work?
I'll focus testing on SSB over the next day or so.
73,
Charlie

 

Charlie . . .

On Sat, 18 Feb 2023 14:29:32 -0800, "Charlie Fellenbaum - WB4FAW"
<charlie@...> wrote:

But I can hear no evidence that they work, at all. This is disappointing and disturbing but before I ask the seller for a refund, wanted to see if someone here has experience and guidance.
Can you take off the cover and see if the filters are bypassed?


Donald KX8K



----------------------------------------------------
Some ham radio groups you may be interested in:
/g/ICOM /g/Ham-Antennas
/g/HamRadioHelp /g/Baofeng
/g/CHIRP

 

Charlie,

I was thinking about this, and if you got a speaker that is supposed to have
audio filters but they don't work, maybe you can get a partial refund to make it
worth your while to just have a matching speaker.

Then, make something like this (or buy the kit):


($25.00)

and supply 12V to the speaker, and you'll have a superior audio bandpass filter
(assuming the one your speaker had used passive components and wasn't powered).

I have a Yaesu speaker that matches my 767GX radio and it has the passive audio
filter gutted. I don't know why it was removed but I understand passive filters
don't work nearly as well as an active filter.

Of course, if you don't want to do that, and want to get a refund (if it's not
working or it's damaged), do that and find another one with a working filter.
Just be aware you can end up with something better if you use an active filter.


Donald KX8K




On Sat, 18 Feb 2023 19:15:59 -0500, "Donald Hellen" <donhellen@...>
wrote:

Charlie . . .

On Sat, 18 Feb 2023 14:29:32 -0800, "Charlie Fellenbaum - WB4FAW"
<charlie@...> wrote:

But I can hear no evidence that they work, at all. This is disappointing and disturbing but before I ask the seller for a refund, wanted to see if someone here has experience and guidance.
Can you take off the cover and see if the filters are bypassed?


Donald KX8K



----------------------------------------------------
Some ham radio groups you may be interested in:
/g/ICOM /g/Ham-Antennas
/g/HamRadioHelp /g/Baofeng
/g/CHIRP




----------------------------------------------------
Some ham radio groups you may be interested in:
/g/ICOM /g/Ham-Antennas
/g/HamRadioHelp /g/Baofeng
/g/CHIRP

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