Topics

Louder??


Curt M.
 

Has anyone made any modifications to make the audio louder?  I'm not smart enough to do it but it would be interesting if someone could come up with a small amplifier circuit that could be put between the speaker connections and the speaker to give it more volume.  I tried one of these little eBay 1w amplifier boards but there must have been some issues with coupling between the speaker out and the input pf the amplifier board because I just got sort of a squeal.  There's probably some type of impedance matching or attenuation that needs done to make something like that work becuase it didn't work for me.  My hearing is not the best but I was kind of expecting the volume of this kit top be nearly on par with a typical transistor radio.

I know doing something like this would not be good for battery life but I'd really love to set this on my kitchen counter or desk and be able to hear it 4 or 5' away.  I have to have my ear about a foot away or closer to make use of the radio.  I love the look of this radio and it was a fun kit to build.  I did all of the suggested mods but I think it falls short when it comes to output volume.  I probably wouldn't have built it had I known the audio output was so low and yes, part pf that has to do with my hearing but I have a bunch of small radios that's I have no problem hearing that run off of (2) AA batteries or (1) 9V battery.  There must be someone on the board that can resolve this with some type of eBay add on board and a few components?

Curt M.


Dave Benson
 

Curt-

Anytime there's a boatload of audio gain, there's always the possible of feedback causing a squeal or motorboating.    Often with an add-on amplifier, it may be necessary to run that on a separate supply.  This doesn't have to be a second battery, though.  If there's enough supply voltage available, a low-dropout voltage regulator may work wonders for isolating the two blocks of circuitry. It can be installed to feed either the outboard amplifier or better yet, the Murania circuitry itself.

73- Dave, K1SWL


On Wed, Feb 5, 2020 at 11:00 AM Curt M. <WU3URADIO@...> wrote:
Has anyone made any modifications to make the audio louder?  I'm not smart enough to do it but it would be interesting if someone could come up with a small amplifier circuit that could be put between the speaker connections and the speaker to give it more volume.  I tried one of these little eBay 1w amplifier boards but there must have been some issues with coupling between the speaker out and the input pf the amplifier board because I just got sort of a squeal.  There's probably some type of impedance matching or attenuation that needs done to make something like that work becuase it didn't work for me.  My hearing is not the best but I was kind of expecting the volume of this kit top be nearly on par with a typical transistor radio.

I know doing something like this would not be good for battery life but I'd really love to set this on my kitchen counter or desk and be able to hear it 4 or 5' away.  I have to have my ear about a foot away or closer to make use of the radio.  I love the look of this radio and it was a fun kit to build.  I did all of the suggested mods but I think it falls short when it comes to output volume.  I probably wouldn't have built it had I known the audio output was so low and yes, part pf that has to do with my hearing but I have a bunch of small radios that's I have no problem hearing that run off of (2) AA batteries or (1) 9V battery.  There must be someone on the board that can resolve this with some type of eBay add on board and a few components?

Curt M.


ohwenzelph
 

I think that after the mods the performance clarity and selectivity seemed better but the volume a bit less and have wondered the same thing.


ohwenzelph
 

Is there a better choice for Q1?


matthew cook
 

I too would like to see better audio out of mine. Holding it up to the side of my head to hear it is the only reason it sits on my shelf unused..


Curt M.
 

I’m not skilled enough at the component level to find the solution but I have to believe that someone on here will have the answer. As it was mentioned above, the mods made a very big difference in clarity and selectivity but I think the missing part of the kit is the volume. It’s funny because when I showed a few people in my radio club they all say, “turn it up some”. I tell them that as loud as it goes. Then they say, “if it was louder I’d really like to build one of those”. Too bad we all found this out after building it.  It’s such a cool looking radio but just falls short in the volume department. 

Curt M.


ohwenzelph
 

After some reflection, it has occurred to me that when building a radio with my grandson, it may well be that limited volume may well be a positive feature for his mother, my daughter...!


ohwenzelph
 

Hi Matt,
You do have to mess with that little loop of wire “L2”, just in case you haven’t. 
It might make a significant difference if you get it just right.
fwiw
jer aa1of


ohwenzelph
 

Does the volume vary with the speaker impedance? The ones in the photo section seem to be 8 ohms, mine is 16 ohms. Would 4, 8, or 16 be best? Or does it matter?


ohwenzelph
 

fwiw
I have tried a variety of small speakers, 4 8 16 25 32 and 45 ohms, the impedance does not have a noticeable significant effect to my surprise, larger ones seem to make more sound than smaller ones, among those that would fit I have not found one that sounds better or noticeably louder than the ones that come with the kit. A couple that were too large to fit seemed to sound a bit better, and the very largest of my small speakers sounded a bit louder.
 
Having done the mods, my volume control seems to work: nothing at all for affair amount, then rapidly goes to max volume and then no further increase the rest of the way.

73s