mic questions

[N7BDY]

I have a couple of very nice , clean old mics that I have gotten ahold of recently and never used yet .  One is a Turner Super Sidekick , and the other is a Turner +3 .  They look the same except for color . But according to what I read the Sidekick is an amplified mic , the +3 has an amp AND a compressor built into it .  Anybody used a +3 on AM and how did it sound ,  is the compressor effective with controlled carrier ?  I dont see why not ,  but I'll ask the experts and see if there is anything I need to be aware of  .   It'll go on my Heath DX-60 eventually , but I need to finish up doing some work on it before it gets on the air .     

N7BDY
Bob

[KX5JT]

If you have a stock DX-60, you might consider a D-104 (non-amplified).   The 12ax7 speech amp is pretty hot and in this operators opinion, you do not need an amplified mic.  The hi-Z crystal element matches really well with the speech amp input and the D-104 sounds really nice and clean with plenty of punch.


As far as the Turners, the best thing to do is to put them on the air and get some reports then decide but I have a feeling you'll have to barely open the audio gain pot on the chassis of the DX-60.

[k4kyv]

If you have a stock DX-60, you might consider a D-104 (non-amplified).   The 12ax7 speech amp is pretty hot and in this operators opinion, you do not need an amplified mic.  The hi-Z crystal element matches really well with the speech amp input and the D-104 sounds really nice and clean with plenty of punch.

Not sure what the first stage grid resistor is for the 12AX7, but I would recommend increasing it to at least 5 megohms if the stock value is less than that.  The "harsh" sound that the unamplified D-104 is famous for is usually due to loading down the crystal element with too low a resistance. I have heard of some commercial rigs that use a 47K resistor at the first grid... tin-can telephone!

[N7BDY]

I dont have a D-104 at the moment .... I have a box of old mics but I'm sure no desk mics are in that collection .  Mostly old CB hand mics and orphans I've accumulated over the years .  I'd like to put one of these Turners into play , they are supposed to have great audio .  Both of them have a knob topside to set the gain ,  and a pot underneath to set gain via a small screwdriver .   AND I noticed the +3 has a small slide switch underneath .... maybe that shuts off the amp    of course that would knock out the compresser     I'll have to do some research and see what I have here .  And I have the gain control on the xmitter too .  Or as suggested change a resister in the audio stage to tame it .  Eventually I want to do the audio mods ,  but first I need to get it going . 

[Pete, WA2CWA]

Tuner +3 and Super Sidekick are classic CB mikes. Audio response is restricted (hardly any lows), mid is very pronounced and no high frequencies. They have great talk power especially on SSB if you're into contesting and breaking a DX pileup.

Turner +3 Specifications
Cartridge Type - Ceramic
Output Level - Max output  -23db, adjustable (0db = 1 volt per microbar)
Output Impedance - 5000 ohms
Frequency Response - 300 to 3500 Hertz
Battery Drain - 1.2 ma (approx 6 months normal use service life, 9V)
Switching - Adapts to relay or electronics
Cable -  3-conductor, 1 shielded, coiled with black PVC jacket

Super Sidekick has roughly the same specs and has speech compression.

[KX5JT]

If you have a stock DX-60, you might consider a D-104 (non-amplified).   The 12ax7 speech amp is pretty hot and in this operators opinion, you do not need an amplified mic.  The hi-Z crystal element matches really well with the speech amp input and the D-104 sounds really nice and clean with plenty of punch.

Not sure what the first stage grid resistor is for the 12AX7, but I would recommend increasing it to at least 5 megohms if the stock value is less than that.  The "harsh" sound that the unamplified D-104 is famous for is usually due to loading down the crystal element with too low a resistance. I have heard of some commercial rigs that use a 47K resistor at the first grid... tin-can telephone!

The stock DX-60 has a 1 megohm grid resistor. 

[W3GMS]

I dont have a D-104 at the moment .... I have a box of old mics but I'm sure no desk mics are in that collection .  Mostly old CB hand mics and orphans I've accumulated over the years .  I'd like to put one of these Turners into play , they are supposed to have great audio .  Both of them have a knob topside to set the gain ,  and a pot underneath to set gain via a small screwdriver .   AND I noticed the +3 has a small slide switch underneath .... maybe that shuts off the amp    of course that would knock out the compresser     I'll have to do some research and see what I have here .  And I have the gain control on the xmitter too .  Or as suggested change a resister in the audio stage to tame it .  Eventually I want to do the audio mods ,  but first I need to get it going . 

If you don't like the sound of your CB mic's, you could always change the element to something else.  Personally I would not use the CB mic's compressor if you do that.  If your trying to get good audio quality I would simply use a good mic element going into the rig as a starter.  The Radio Shack electret mic elements are really cheap and very good.  Steve, WA1QIX has used them for years and has obtained outstanding quality from them.  Steve runs legal limit so he has the carrier to back up the full range audio.  Often times with a low power rig you want to not have wide range audio with lots of lows.  Your signal will not be strong enough to support that in many cases.  Ideally what you want is good low distortion audio with good mid range presence.  To many lows takes you in the wrong direction.  If the electret element has to much bass, you can use a series coupling cap to roll off some of the low frequency content until you obtain a good balance with good mid range presence.  If you do use an electret element, you will need a small thin piece of foam in front of the element to act as a wind screen. 

Have fun....

Joe, W3GMS     

[k4kyv]

You need for the highs to balance the lows.  There is a difference between too much bass and not enough treble, and vice versa. I forget the figure (I have it somewhere) that for a given low frequency limit you multiply the high frequency limit and come up with a constant.

1 megohm is too low resistance for the D-104, or any other crystal mic.  Think of a crystal mic as an ideal a.c. generator with about a 500 pf capacitor in series.  To exploit the full low frequency range you need an extremely high resistance/impedance load.

From my own admittedly biased POV, no self-respecting ham will use a hand mic/PTT switch combination with spiral cord, outside of a vehicle.

[K5IIA]

From my own admittedly biased POV, no self-respecting ham will use a hand mic/PTT switch combination with spiral cord, outside of a vehicle.

that is an awesome quote. 

[N7BDY]

I hear ya on the hand mics Don ,  thats why I have a box full of the things not being used  ,  they are a PITA to use at the desk .   OK  ,  so it looks like the Turners are good mics ,  just restricted audio responce suited more for SSB than  AM ..... I have 'em so I'm going to try them , but keep my eyes peeled for something better suited .   Basically I just want something that sounds nice and full for ragchewing .  Personally I like a bit more of a basey sound to it .  Everybody is different but thats what I like to hear .   

What is the normal audio responce of the stock DX-60 ?   And after the audio / cap mods what do I expect it to be ?   That'll give me an idea what to look for in a mic .  Joe ,  I agree  Rat Shack does have mics and some sound really good .  Cheap too .  Or maybe an old public address system mic will turn up somewhere .   Sometimes it just boils down to trying a bunch and see what sounds best .  I have some desk mics but all dedicated for other rigs .  Dynamic ,  crystal ....  any preferences ? 

I appreciate the help guys and any more advise welcomed . 

N7BDY
Bob

[K5UJ]

I worked a guy about a week ago who was running a DX60B with one of those turner mics.  to my ear he sounded slightly distorted on his audio peaks but I am not any kind of expert especially on the sound when it comes to controlled carrier rigs.  He had a D104 on hand and I had him try it.  I thought the D104 sounded better (clearer) but it also had reduced audio level.    He said the mic gain control is inside the cabinet.     I advised him to get an oscilloscope (he did not yet have one available for use) and use it to look at the rig's output under modulation and listen to it into a dummy load with a separate rx. 

[VE3LYX]

I run a DX60B daily on AM. I have to really watch I speak loud enuf to get good mod %. I have tried three differet mics. The CB mike was the worst. It had a sprial cord BTW. Go ahead. Ask me if I care ;>) Didnt worry about audio quality I was lookiing for punch.
IMHO with a low power rig like a Dx60 or DX60B far too much time is spent trying to get Broadcast audio quality. What one needs is punch. In a screen moduilared rig you need good punch to keep averge screen voltage peaks high enuf for good power. You have to speak boldly and not trail off if you are working fringe distances. I would gladly trade  some audio quality for good punch and intelligability. After all I am not singing . I am carrying on a QSO. It is hard I realize for anyone with a KW or so , fans running and lights dimming to grasp the concept and challenge of working your tail off to see what you can do with a Low power AM rig. Some of us warped individuals find that fun though. My own favourite sound is Communications style . Clear and strong. If I was heating my shack with a glowing linear I might feel different but I am not. Sold the silly thing 20 years ago.  I have been able to improve my DX60B s performance. Not in huge amounts but a wee bit better every week or so. I never quit rubbing on it and find that challenge of great interest. Always ready to try another mic. I have squeaked up the gain and played with the loading circuit (which is just a wee bit light in vitamin C.)  I found this mic discussion interesting. I would like to at least try a D104 but havent had the chance yet. Hamfest this weekend in Pickering. Who knows what we might find?
Don VE3LYX

[KB2WIG]

My D 10-4 has a spiral cord.


klc

[k4kyv]

My D 10-4 has a spiral cord.

That's what makes the difference between a D 10-4 and a D 104.