[Elecraft] Fwd: Yet another D104 mic wiring question.

[Reuben Popp]

Whoops, meant this to go the reflector (sorry Don!) :)


A little bit of progress.... maybe.

I went ahead and rewired the T-UG8 base back to the original schematic to
ensure that it was as "stock" as could be.  I also noticed that the
original crystal element (under the insulating material) looked like
someone pushed it in some (and it had a small pinhole).  I decoupled it and
replaced it with a Shure 99E86 element that I had lying about.

On the radio side of things, I went through the KSB2 alignment procedures,
just to be sure.  SSBA is set to a 3, SSBC is set to 2:1 (at least I think
that's right.. the manual and radio is in the garage).  Last but not least,
I also turned the D104 5K pot to a hair above its bottom extremity.    Now
blowing or whistling or just plain talking into the mic will cause the K2
to cut out with a slight bzzt*pop* [from the radio] as the s-meter goes all
the way to the right and then goes dark.  This happens every time.

That said, that Shure element is medium impedance as far as I know, about
300 ohms IIRC.  At that point, can I (or should I?) completely bypass that
preamp?  Can anyone provide an example schematic on the routing without the
preamp?  Is it safe to just use the schematic from the unamplified UG8 base?


Thanks again to all and 73

Reuben


On Nov 4, 2015 9:32 AM, "Don Wilhelm" <w3fpr at embarqmail.com> wrote:

> Reuben,
>
> You have it wired correctly.  Pins 7 and 8 are connected together in the
> K2.
> Does the K2 go into transmit when you close the PTT switch?  If so, that
> part is good.
> You may want to check continuity from the mic base to the plug for the
> white (AF) and the Shield (AF return or MIC GND, just to assure yourself
> that the mic cable is intact.
>
> Another continuity check that you can do is between the white wire in the
> base of the mic (with the mic plugged in) to KSB2 P1 pin 5 - that will
> verify that both the mic cable and the K2 wiring for the AF signal is
> correct and intact.
>
> 73,
> Don W3FPR
>
> On 11/4/2015 10:10 AM, Reuben Popp wrote:
>
> Hey Don,
>
> I had replaced the original four pin connector with an eight pin according
> to a post I found online for a Kenwood TS-440:
>
> 1 - MIC
> 2 - PTT
> 3 - DOWN
> 4 - UP
> 5 - NC
> 6 - NC
> 7 - MIC-GND
> 8 - COMMON (PTT GND)
>
> "The mic came with an old four pin connector.  The cord itself has three
> wires plus the copper braid/shield:  black, red, and white.  In wiring it
> to a standard eight pin female, white went to pin 1, red to pin 2, copper
> braid to pin 7, and black to pin 8.  On the P2 jumper, I jumpered it as per
> the KSB2 manual for Kenwood for AF, PTT, and the two grounds."
>
> It's quite possible I might have goofed something up here, but I *believe*
> I have it set correctly.  The only thing I can think of is that maybe I
> have the mic ground and PTT ground swapped?  Is the copper braid the PTT
> ground?
>
> Thanks again and 73
> Reuben
>
> On Wed, Nov 4, 2015 at 8:29 AM, Don Wilhelm <w3fpr at embarqmail.com> wrote:
>
>> Reuben,
>>
>> You only need 4 jumpers on the K2 Microphone Configuration Header - AF to
>> 1, PTT to 2, and ground at pins 7 and 8.
>>
>> Since you found that the microphone wiring had been altered, have you
>> checked the wiring from the mic base to the 8 pin plug?
>> the AF should connect with pin 1, PTT connects to pin 2.  Connect the AF
>> return to pin 8 and the PTT return to pin 7.
>>
>> Do you have a Kenwood microphone or can you borrow one from a fellow
>> ham?  That no-name microphone will likely work if you wire the mic plug
>> correctly.
>> See if that microphone works on your K2.  That test will tell you whether
>> to look in the K2 or into the microphone for the problem.
>>
>> 73,
>> Don W3FPR
>>
>> On 11/4/2015 9:13 AM, Reuben Popp wrote:
>>
>>
>> Just as a followup, at the time I didn't have enough jumpers to put one
>> on every set of pins on the mic header.  Is that my issue here?  If so,
>> that part wasn't overly clear in the KSB2 instructions, at least to me, lol.
>>
>> Other than that, I'm running out of ideas here.  I have a no-name dynamic
>> hand mic from a parts bin that I will wire up tonight to see if that works,
>> but after that....
>>
>> The only other thing that I can think of is maybe one of the components
>> in the base is bad, whether it's the pot, the switch or something on the
>> amp board.
>>
>> Thanks again to all and 73
>> Reuben
>>
>> On Mon, Nov 2, 2015 at 6:17 AM, Don Wilhelm < <w3fpr at embarqmail.com>
>> w3fpr at embarqmail.com> wrote:
>>
>>> Reuben,
>>>
>>> You have the mic configuration header wired correctly.  Any chance that
>>> the potentiometer in the mic is set to its low point?
>>> I suspect that microphone.  Many of the amplified D-104 mics have had
>>> the preamp in the base modified.
>>> As a test, see if you can borrow a Kenwood dynamic microphone from a
>>> local and see if that works.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>>
>>> On 11/1/2015 10:30 PM, Reuben Popp wrote:
>>>
>>>> That said, on keying the mic, the K2 goes silent but there is no
>>>> evidence
>>>> on the S meter that anything is happening.  FWIW I have replaced the 9v
>>>> battery in the base and attempted the same after adjusting the preamp
>>>> pot
>>>> to each extreme.  Do I need to jumper the other pins on P2 as per the
>>>> KSB2
>>>> instructions?  Do I have the female connector wired correctly?  Or
>>>> perhaps
>>>> I should revisit the wiring on the preamp and make sure someone else
>>>> didn't
>>>> Bubba it in the past...
>>>>
>>>>
>>>>
>>>
>>
>>
>
>