Thumps

w7com · Post by **w7com** » Thu Jan 01, 2004 1:36 pm

The locals are switching from a simplex VHF system to a Type II trunking system. While they were on VHF I did very well monitoring them with a Maxtrac on a "Ringo Ranger". One of the reasons I use Mot radios was the very clean sound and lack of any thump or squelch tail at the end of a transmission. Of course the same is true with my HTs and mobiles.

This week the sytem is starting to simulcast with the trunking system so I've setup a Spectra for monitoring. I've noticed that the Spectra, at the begining and end of a call, gives a loud thump, even with the volume set to zero. It sounds like the radio sends a good amount of DC offset to the audio amplifier when it mutes and unmutes. Also the audio sounds crap compaired to the SyntorX 9000/MT1000 based VHF simplex system.

Is this what I'm going to have to live with now?

wazzzzzzzzup · Post by **wazzzzzzzzup** » Thu Jan 01, 2004 2:39 pm

STX portables are like that too, so dont consider a TYPE II STX portable

but to me, the STX's "thump" makes it very unique, almost as if thats just how the stx has always been.
i used a STX back when they were the mack daddy and they even had the thump then. as for the spectra, i am trying to get 4 900's up and running now, so i will update you if they have the same problem you have.

wazz

ricciticcitembo · Post by **ricciticcitembo** » Thu Jan 01, 2004 2:43 pm

Yup pretty much. The Spectra has a Balanced Floating output IC that turns On and Off every time it hears something. Over 6 Volts last I checked, good for a nice "pop" sound. Stupid Spectras, Get used to it.... It puts out enough DC to drive a Relay for COR and that ain't no Bullsh!t.

Or Maybe, just maybe we could come up with a way to get line-level out, and use a different Amp with no DC Bias on it, I dunno, but it's on my list of things to try, since I don't like the Popping sounds either.

The audio IC works the same on all bandsplit Spectras. Whith a Thump of DC.

w7com · Post by **w7com** » Thu Jan 01, 2004 2:43 pm

Actually I also have a STX821. That's why I was wondering if this is a trunking thing or if I've not programmed them right.

ricciticcitembo · Post by **ricciticcitembo** » Thu Jan 01, 2004 2:47 pm

It's not a trunking thing, it's an output IC thing, thats why it still thumps with the volume at zero.

w7com · Post by **w7com** » Thu Jan 01, 2004 2:48 pm

So, do the VHF/UHF conventional Spectras do the same thing?

ricciticcitembo · Post by **ricciticcitembo** » Thu Jan 01, 2004 2:50 pm

Yup. mine do. they All got 6VDC across the speaker terminals with the volume at any position.

VHF/UHF lo/HI 800 and 900.

So unless ALL my Spectras are busted, I'd say this behavior is normal.

w7com · Post by **w7com** » Thu Jan 01, 2004 2:57 pm

I guess that will rule out any spectras for my conventional use. I learned my electronics in broadcasting and thumps like that were NOT allowed! I'll have to dig up a schematic of the audio section and see if it could be fixed.

wazzzzzzzzup · Post by **wazzzzzzzzup** » Thu Jan 01, 2004 3:02 pm

possibly a 1:to 1: audio transformer? it would pass the AC audio but block the DC.

007 · Post by **007** » Thu Jan 01, 2004 3:05 pm

All of my Spectra's do the same....damn annoying sometimes!

w7com · Post by **w7com** » Thu Jan 01, 2004 3:36 pm

wazzzzzzzzup wrote:possibly a 1:to 1: audio transformer? it would pass the AC audio but block the DC.

That will remove the DC but you'll still hear the thump. It's AC when it's "thumping." ricciticcitembo is right, you'll have to dig into the radio to find a good spot to pull the audio pre-thump. Maybe grab an amplified speaker from a convertacom, take the detected audio from the back of the spectra, pop in a de-emph filter and a quiet switch to mute the audio, figure someway to deal with volume control... arrgh!

A lot of work for something Motorola should have done right in the first place.

ricciticcitembo · Post by **ricciticcitembo** » Thu Jan 01, 2004 4:34 pm

Very annoying....

But on the plus side, I don't hear it when used as a Repeater since the thump is shorter than the TX Key-up Time. So thats a good thing #1.
Good thing number 2 is the DC used as a COR line.

So it ain't all bad....

Jim202 · Post by **Jim202** » Thu Jan 01, 2004 4:41 pm

Are you sure its not some of the capacitors going south on the Spectra. The normally have nice clean audio. All the ones i have in trunking operation don't seem to have the issue your talking about. The VHF ones ALSO DON'T SEEM TO SHOW IT EITHER.

jIM

wazzzzzzzzup · Post by **wazzzzzzzzup** » Thu Jan 01, 2004 4:48 pm

what is COR?

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Thu Jan 01, 2004 4:51 pm

wazzzzzzzzup wrote:what is COR?

Carrier Operated Relay [or something like that anyway]

It's a repeater term for a line that goes high [or low] when a radio transmittion is recieved.

And speaking of thumps, my Vx-150 thumps too. Darned annoying if you ask me.

ricciticcitembo · Post by **ricciticcitembo** » Thu Jan 01, 2004 5:26 pm

OK Jim, you might have something there. They are like 10 years old, almost all of mine are that old according to the Serial Number Year code. I know for sure the 800's are problematic, and my UHF 450-480 range3 does it too. I Also know for certain that ALL Spectras have a DC bias present on the Speaker Terminals, and that is Due to the Fact of the Poor Choice of Audio Output Amplifier IC - The TDA-7256 which is direct-coupled to the speaker via Complementary NPN and PNP Transistors. This is why the Voltage Present on the Speaker Terminals is exactly half of the Powersupply voltage minus one .7 volt drop referenced to ground.

So this accounts for some of the Thud on all Spectras, BUT- I'm sure if any of the audio caps elsewhere in the circuit are aging it might very well increase the loudness of the thump. 800 Trunking radios DO seem to have a slightly louder thump than its VHF and UHF brothers and sisters. For whatever reason I do not know,.

And Jim you did pique my curiosity on the VHF, and I just checked mine. With my ear to the speaker, tapping on the volume down button, after it is all the way down to zero, everytime you push on the button, you hear the Thump, click, noise, or whatever you want to call it coming from the speaker, as the Audio Chip in the Spectra powers up only when it wants to make a sound. VHF models Included by my observations. And that is the one radio I have that's only about 5 years old, so the caps should be still good in it.

-Everybody else-

you should All be aware that this THUMP W7com, Jim and myself have been muttering about is really not as bad as we are making it sound. In fact some people might not even notice it at all. But I notice every audio anomoly known to man it seems, I can't Stand the horrible noises coming from Nexhells, and they are not going to be able to fix that problem anytime this century, and those noises are Far Worse than the Stupid Spectra Thumping noise we are discussing here.

SABERS Thump Too. Same output Scheme. Not nearly as noticeable though, less voltage to the speaker I guess, about 3 and a half. not really all that bothersome, It's barely audible, even by my standards. It shows a Nice Thump on the Oscilloscope though!! At least It's not as loud as the Spectra Thump, which like I said before, you have to be "Picky" or an audiophile to notice that these radios even make this "Thumping" noise.

Any noise is agravating. Thats why they call it noise, and not signal.

And 800 Spectras are the Thumpiest ones.
And like Jim Said, the VHF one is so quiet you have to put your ear to the speaker to hear it, and it's more of a "Click" than a Thump. The 800 Definately Thumps though. It ain't no click, It's got some Bass to it. LOL.

wazzzzzzzzup · Post by **wazzzzzzzzup** » Fri Jan 02, 2004 12:19 pm

this dashmount 900 meg spectra made in 1990 "THUMPS" when audio starts or stops.

mancow · Post by **mancow** » Fri Jan 02, 2004 4:14 pm

I had to sit in the car for 3 hours straight watching a house the other night. I had the spectra's volume at about 2 or 3 at most. I never heard the sound at all and I was using both an 800 and vhf spectra. Then again the only thump I heard was my head on the window as I tried to stay awake.

The BK E series radios are terrible. I can hear it across the room. It drives me nuts when I'm trying to type and the other guys have theirs down so low all you hear is CLICK, POP, CLICK

I noticed that in the BK there is a transistor that powers up the audio amp each time a signal is received for battery saving purposes. I wonder if I kept the amp on with 5 volts all the time by defeating the transistor would it stop this?

mancow

Jay911 · Post by **Jay911** » Fri Jan 02, 2004 7:13 pm

We have a Spectra 800 Smartzone at our backup center. I spent 3 shifts there one week while the line from the backup center, where the towers come in, to our main center (don't ask) was being repaired. I thought it was just the way they had it set up (like a powered external speaker or something) that made the radio go THUMP every time a transmission started or ended!

--j.

Jay911 · Post by **Jay911** » Fri Jan 02, 2004 7:54 pm

I don't know, this was early this spring at least. I'm going to assume digital, since it had digital talkgroups in it (Police) as well as our analog ones.

--j.

ricciticcitembo · Post by **ricciticcitembo** » Tue Oct 19, 2004 9:02 pm

Update- Well after installing those old 500 Watt Targa Amplifiers (circa 1985)
that I had in the van into the Honda along with a Brand NEW Full Set of those
Deluxe MB Quarts all the way around (They are SUPER!), I decided
I can not Stand the Thumping any More because it is ruining my stereo quality.
It is bad enough the Main County 800 Trunking system is weak and noisy
and I don't need any more noise coming from any Spectras
being amplified to 1000Watts. OK since they are Targas and they lie
a lot, better figure on maybe a hundred watts. But it still was bad.

Soulution- Take the screw out of the TDA series amp chip in the Spectra.
Wiggle it back and forth until it breaks off, and throw it in the trash.
Next, take out the pins with the solder sucker.
Clean off the silicone grease with Trichloroethelene or something non-toxic.
Double stick tape a nice Omron or Potter and Brumfield relay in it's place.
use a diode across the coil terminals to prevent HV backfeed into the spectra.
Use the turn on signal that used to power the amp chip to turn on the relay.
Grab your signal from the j501 header connector (the HLN6000B plug)
route signal through relay and out to the existing speaker leads already present where the chip used to connect to.
Amplify and buffer said signal through an A/D/S crossover (AX3).
Connect to the Mixer and your done.

WOO HOO!! NO MORE THUMPING AT ALL. FINALLY.

It's too bad I didn't have the service manual handy when I did this,
and the radio is already installed or I'd tell everybody where the pins are.
But it ain't that hard to figure it out, it only took me like 10 minutes
and I only used my home stereo as the test equipment.
Besides, if you need specifics after I already explained what to do,
then you should NOT even attempt this.

But trust me, it works like a champion.
Sometime when I'm in a good mood and bored to death, I'll design a nice solid state gate circuit and trash the relay. But for now, I'm very very happy with the ultra clean unadulterated audio.
The way it should have been in the first place.

I am also going to completely change around my Spectra Repeater
to reflect these changes since the audio is so outstanding this way.
Most likely will have to add some logic and external switching due
to the securenet using different paths and the Spectra
auto-switches this through some VLSI Chip whos name escapes me at the moment.
That signal has already been Messed up already and I Won't be using that.
I Prefer the raw decoded signal directly from the HLN6000B,
and post process with an A/D/S.

It's like Night and Day. Big F'n Difference.

I hate to say it but the Spectras stock audio just plain sucks. Real bad too,
And it is now very apparent since I fixed one unit.

-Later

P.S. be CAREFULL when installing the MB Quart Crossovers in the doors.
They are kinda big, and you must be cautious that the windows don't hit them.

Will · Post by **Will** » Thu Oct 21, 2004 3:48 pm

Thumping Spectras... yes that is an indicator of other problems in the Spectra as they are getting older. I have done some serious troubleshooting, engineering, to find out why and it is the audio amp circuit. At first I went on a hunt for a replacement audio PA chip, but that wasn NOT the problem afterall. I put some of the info in my Spectra FAIL001 post.

When I got the problems resolved the Spectras no longer "thumped" on unsquelch or squelch close, not even on Scan anymore. They can be fixed, now that I know what to do.

First test, with a simple dc voltmeter, read the DC voltage on the two speaker leads, NOT ground.. Should be less than .01 volts DC across the speaker when the radio is unmuted, receiving, at any volume setting. If the DC voltage is greater than .3 volts DC, then it is time to get the radio repaired.

There are three other areas that go bad, usally at the same time or shortly after, FAIL001, noisey receive and transmit, and eratic TX power output. They can all be corrected for less than $80....

Cowthief · Post by **Cowthief** » Thu Oct 21, 2004 4:12 pm

Hello.

I have had no thumping spectras so far.
You can add a non-polarized cap' in series with the output and perhaps reduce this?
The 2 spectras in my automoble all go thru an audio panel, DC isolated, so I may simply not be aware that there is a Problem, will do more checking.
The electrolitic caps in the spectra are known for leaking, so this may be a sign.

mr.syntrx · Post by **mr.syntrx** » Thu Oct 21, 2004 5:36 pm

My A9 UHF Spectra did this, but the condition disappeared when I replaced every electrolytic cap in the radio.

kf4sqb · Post by **kf4sqb** » Fri Oct 22, 2004 9:23 am

I don't know if it is from the same problem or not, but the old GE Phoenix I use at home for a 2m base has this problem. This one is nice and loud, too. With the volume turned all the way down, the thump is clearly audible in other rooms of the house. It has been annoying me for some time now, I just never thought about trying to find out why it did it and try to fix it. I thought that maybe it was normal for these radios, but now I wonder...

Cowthief · Post by **Cowthief** » Sat Oct 23, 2004 1:40 pm

Hello.

I connected two of the radios directly to speakers, no thumping.
The radios have had ALL the electrolitics replaced and retuned by Monty just a few weeks ago.
Now, I usually connect EVERY radio to an audio panel, but.
I connected some ventage spectras to speakers direct, and THUMP!
So, it looks like the thump is indeed an indicator to look at the radio.

ricciticcitembo · Post by **ricciticcitembo** » Sat Oct 23, 2004 8:05 pm

For once I agree completely.
My Worst Spectra not only Thumped, but the audio was distorted,
and had oscillations at all times. That is why I removed the TDA7256.
It was Toasted already when I got the radio.
I replaced all the Electrolytics but it was too late as the Chip was also bad.
That is why I removed the chip and replaced it with a relay and
Line-output of 500millivolts only in that particular radio.
I didn't just Trash the Chip for no reason whatsoever.
I failed to mention that little tidbit in my previous post, so I wanted to be perfectly clear on that.

Thank God that was the only Spectra I had like that.

The rest of them at least just need some new caps. At least the chip is good.

I'm sure eventually I'll get a new chip and return that radio I hacked with a relay back to its normal self again.

I should have titled my previous post as:
"What could be done if the chip is toast, and you need the radio to be working immediately"
(And you already have an external audio amp/mixer panel)

Also one other fact I'd like to make perfectly clear is that if you do
grab the audio Pre-TDA7256 it will be cleaner.
And It will have Remarkably Less Distortion, and will be less Muffled. I Gaurantee it.
Whether the radio has Brand New Caps and Chip or not.

Josh · Post by **Josh** » Mon Jun 12, 2006 8:05 am

This is an old topic and I am reviving it.

I too would like to get rid of the thumps on my "base" style Spectra, it has the desk base with the built-in speaker, not to be confused with the consolette.

At any rate, would it be possible for the voltage across the speaker leads to hold a relay, then when the voltage drops, a circuit to be connected to the speaker?

This would get rid of the 'pre' audio pop.... on my radio, the post 'pop' isn't as much of a problem, it's pretty soft.

I could encase it all in the speaker base and nobody would know, even though I'd want to implement it into all my radios somehow because it's getting rather annoying after these six months.

I guess that's why Motorola pushes the XTL5000 and no longer makes the 'astro spectra'... *sigh*

-Josh

kc7gr · Post by **kc7gr** » Mon Jun 12, 2006 8:24 am

Josh wrote:This is an old topic and I am reviving it.

I too would like to get rid of the thumps on my "base" style Spectra, it has the desk base with the built-in speaker, not to be confused with the consolette.

At any rate, would it be possible for the voltage across the speaker leads to hold a relay, then when the voltage drops, a circuit to be connected to the speaker?

<snippety>

This problem (and it is an actual problem, not a design feature of the Spectras) has been discussed to death in many threads.

The summary: There are a series of aluminum electrolytic capacitors on the RF and command boards that leak and dry out, and start eating away at the boards in the process. The 'thump' is caused by the loss of capacitance as the caps fail.

If this problem is not promptly addressed, once detected, there is every possibility that the leaking electrolyte will damage the RF and command boards beyond repair (the electrolyte is corrosive).

SPECTRA OWNERS: If you hear an audible 'thump' as your radio mutes and unmutes, CHECK THOSE CAPS! They may not show visible signs of leakage until removed from the board, or until you start seeing corrosion signs around them.

Josh · Post by **Josh** » Mon Jun 12, 2006 8:51 am

*sigh*

NOT A CAP ISSUE

A SPECTRA INHERENT ISSUE.

Good gawd, I don't read a million threads with the same information and then ask the same questions.

"caps" this and "caps" that comes up every other week and with the same thing.. "check the caps" "check the caps" "check the caps".

The radio could be brand f'ing new and I bet that'd be the same response I'd get.

How about a functional resolution folliowing the lines I drew out in my original post? There isnt' anything that's going to fix a crappy-ass audio amplifier.

and FYI, this is for Astro Spectra... there's only one capacitor on the command board anywhere near the Audio Amp....unlike the analog spectra's 4.

-Josh

jackhackett · Post by **jackhackett** » Mon Jun 12, 2006 11:11 am

Normally there should be no DC voltage 'across the speaker leads' of a spectra, if there was the speaker would not only sound pretty crappy, but would also likely not last very long.

Now, the problem with the spectras is that moto decided that instead of using the mute input on the amp, which should provide popless muting, they were going to mute it using the standby input. I don't know why they did it this way, perhaps using the mute input opens the audio too slowly for this application, they probably made a tradeoff for the slight popping figuring the radios weren't meant for audiophile use. Personally I've never noticed a problem with them unless they actually had the bad cap problem.

I suppose you could try modifying it to use the mute input, but I couldn't guarantee the results, that's a pretty expensive radio to be chopping up. Another idea would be to use the mute signal through a short delay to keep the speaker disconnected when the amp first turns on, again I wouldn't guarantee it will work.

kc7gr · Post by **kc7gr** » Mon Jun 12, 2006 12:06 pm

Josh wrote:*sigh*

NOT A CAP ISSUE

A SPECTRA INHERENT ISSUE.

Good gawd, I don't read a million threads with the same information and then ask the same questions.

"caps" this and "caps" that comes up every other week and with the same thing.. "check the caps" "check the caps" "check the caps".

Josh wrote:
and FYI, this is for Astro Spectra... there's only one capacitor on the command board anywhere near the Audio Amp....unlike the analog spectra's 4.

That's the FIRST TIME you mentioned 'Astro.' Since you did not specify that in your original post, I assumed that you were referring to the analog Spectras. I think others probably did the same.

You also made no mention of the fact that you were already aware of the issues with the caps. A simple addition to your original post of "I'm aware of the problems with leaky electrolytics, and this is unrelated to them" would have been all you needed to say.

It is not wise to get mad at people for speaking their mind when you did not provide enough information to begin with.

Now, with that said -- Perhaps, rather than butchering a part of the command board to add a clunky relay, and using an external audio amp, it might be possible to modify the original circuit to function a little better. Personally, I've never noticed any 'thump' in a properly-functioning Spectra, Astro or Analog.

This is enough to get me curious. I will look at the spec sheet of the TDA7256 later, and see if there is a Better Way to do muting.

And, for the record... For the 30+ analog Spectras I've looked at to date with the excessive 'pop' or 'thump' problem, replacing the suspect caps AND (in some cases) the audio PA chip, COMPLETELY CURED THE RADIO.

I'm sorry if you're upset, but the truth of the matter is that it is very often the caps that are at fault. Again, don't blame others for assuming that what you describe is a common problem if you do not provide enough context to work with.

jackhackett · Post by **jackhackett** » Mon Jun 12, 2006 12:47 pm

kc7gr wrote:

Personally, I've never noticed any 'thump' in a properly-functioning Spectra, Astro or Analog.

Good.. I was wondering if it was just me that didn't hear those thumps, but then I'm an aging, drunk priest, it's easy for me to miss these things...

Josh · Post by **Josh** » Mon Jun 12, 2006 1:00 pm

idk

I see one simple solution

I don't use high volumes on this base desktop thing usually around 4 or 5. Higher volumes present no problems with audio, just low ones, The desk thing has a 2 ohm speaker and was originally meant for an MCX100... if I were to throw a resistor in there of a few ohms to being the resistance a bit higher, much like the toggle on the speaker of the motorcycle spectra, then the noise would be less pronounced then.

Now, I have no intentions on tearing up the command board, that's crazy. I'm referring to an external relay device,

Now, ricciticcitembo earlier in this post from two years ago, wrote "Yup. mine do. they All got 6VDC across the speaker terminals with the volume at any position.

VHF/UHF lo/HI 800 and 900."

Now, the popping stuff isn't an issue to me on my analog channels.... it is rather bothersome on digital though since every transmission opens and closes the audio path rather than a conventional repeater, for instance, with an audible hangtime.

Sorry for going nuts earlier... I KNOW about the capacitor issue with the analog spectra. I have seen too numerous threads than to do the newbie thing and write up the same old questions without first searching.... and even so, I wouldn't have used a thread that answered the cap issue already.

-Josh

kc7gr · Post by **kc7gr** » Mon Jun 12, 2006 2:10 pm

I cannot resist...

Beware of Spectras that go 'Thump!' in the night! (or 'Knight,' if you happen to be a fan of 'Knight Rider.')

Rayjk110 · Post by **Rayjk110** » Mon Jun 12, 2006 3:05 pm

I've got a VHF A7 Spectra (Actually, from Josh), and I don't hear this thump noise you talk about, or even what it is.

Thumps, if any, that I hear, are on the RX'in radio, as in if I de-key my maxtrac or spectra, the receiving radio has a thump that is heard when I de-key.

Also, with any of my radius hand-helds (p1225- sp50- cp200), whenever a speaker-mic is attached, there is a thump sound on de-key heard on the receiving radio. Any idea what that is?

Josh · Post by **Josh** » Mon Jun 12, 2006 6:22 pm

My thumps my thumps... my lovely lady lumps... check 'em out

Ray:

it's the speaker mic that does it. Notice the nice little "popping" sound it makes on its own? It gets amplified by the mic while releasing the PTT.

-Josh

jackhackett · Post by **jackhackett** » Mon Jun 12, 2006 6:31 pm

Josh wrote: Now, ricciticcitembo earlier in this post from two years ago, wrote "Yup. mine do. they All got 6VDC across the speaker terminals with the volume at any position.

VHF/UHF lo/HI 800 and 900."

Each speaker terminal will have approx. 6 volts DC when referenced to ground, but they're at the same potential so 'across' the terminals there should be no DC voltage.

As far as using this voltage to drive a relay, I can tell you that a relatively light load from either speaker lead to ground can cause problems... I've seen where hooking one up to a siren's radio rebroadcast input that had about 1000 ohms to ground, made it lose speaker audio. If you were going to try this I would use a transistor circuit with a high input impedance to drive the relay.

Josh · Post by **Josh** » Mon Jun 12, 2006 8:07 pm

...Sounds like a job for... a higher impedence speaker!

I wouldn't care at all, if I used higher volume levels on the radio, it's these "3" and "4" settings that mess with my mind and make me crazy.

-Josh

Josh · Post by **Josh** » Tue Jun 13, 2006 9:28 am

Good news...

Here's what I did...

I went to Radio Shack

I bought a pack of 10 ohm resistors and wired them in parallel (=5ohms)

I wired it to the 2 ohm speaker 10/2+2= 7 ohms.

I put the desk thing back together....

the result: GOOD AUDIO, and less pronounced popping crap noise.

Satisfied? Yes.

-Josh

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Tue Jun 13, 2006 10:38 am

Josh wrote:I went to Radio Shack

I'm sorry to hear that.

jackhackett · Post by **jackhackett** » Tue Jun 13, 2006 11:13 am

Well crap.... that was too easy.. lol!

What I want to know is.. how did you find resistors at a radio shack? Did they have to take them out of a cell phone for you?

Josh · Post by **Josh** » Tue Jun 13, 2006 1:06 pm

LMAO!

Well, first thing I did was start a diversion, so I sent one of my female friends in ahead of me... with the sales associates diverted, trying to sell cell phones, I made a break to the component drawers where I happened upon what I needed.

It was an adventure in itself, but rest assured they wouldn't let me go without first asking me if I needed and batteries, and to come back to them if I did....

I can't imagine a trip into the bowels of the Congo being any more adventurous than a trip to the local Rat-Shack.

At any rate, I'm content with the results I have... does anyone know what the ohm rating of the speaker in the standard SPECTRA desk stand is? HLN6042 is the part number I have on that.

-Josh

Rayjk110 · Post by **Rayjk110** » Tue Jun 13, 2006 2:09 pm

Josh wrote:LMAO!

Well, first thing I did was start a diversion, so I sent one of my female friends in ahead of me... with the sales associates diverted, trying to sell cell phones, I made a break to the component drawers where I happened upon what I needed.

It was an adventure in itself, but rest assured they wouldn't let me go without first asking me if I needed and batteries, and to come back to them if I did....

So true hahah

Will · Post by **Will** » Tue Jun 13, 2006 3:22 pm

" does anyone know what the ohm rating of the speaker in the standard SPECTRA desk stand is? "

I am not sure, that was back a while. But I find that even a 16 ohm speaker works just fine.

So, one 10 ohm resistor in series with the speaker, should work just fine.

Josh · Post by **Josh** » Tue Jun 13, 2006 3:43 pm

I didn't want to chance blowing up the audio amp with too much resistance, so I kept it below 8 ohms

I did test it ou with a 10 ohm resistor, but opted out since 5 made the audio level acceptable.

-Josh

jackhackett · Post by **jackhackett** » Tue Jun 13, 2006 4:27 pm

Josh wrote:LMAO!

Well, first thing I did was start a diversion, so I sent one of my female friends in ahead of me... with the sales associates diverted, trying to sell cell phones, I made a break to the component drawers where I happened upon what I needed.

I went to the local shack today looking for a project box to put a tone remote adapter in, they had none on display so I asked and was told they were boxed up in the back.. the clerk... errr.. sales associate... went back and came out with a box full of all kinds of stuff that he said the stores were going to stop carrying, besides project boxes there were circuit boards, power transformers, IC sockets, all kinds of goodies.. he says that stuff will still be available online, but if I'm going to buy stuff online I might as well go to Jameco or Mouser.. the only point of getting that stuff at shack was that you could get it right away.
I do like their little circuit boards with the same pattern as a breadboard, I might have to hit a few of the local stores and stock up while I can.

Will · Post by **Will** » Tue Jun 13, 2006 5:32 pm

jackhackett wrote:
snip>
I might have to hit a few of the local stores and stock up while I can.

Jack, you are right on!!

Now I got to get on down to the Shack and stock up!!

Thumps

Thumps

Re: Thumps

Thump.

Caps going bad early warning.

Re: Caps going bad early warning.

I gotta do it...