Quantcast

Soldering Iron Weller WTCP-S / WTCP 51 tip grounding direct or via 1MOhm res. ?

classic Classic list List threaded Threaded
5 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Soldering Iron Weller WTCP-S / WTCP 51 tip grounding direct or via 1MOhm res. ?

Thomas Martin-5
Hello,
knowing that here are some experienced Weller insiders
around here is my question concerning the grounding of the
tip of these two stations.
Since 18 years I have been using my WTCP-S (Magnastat)
with its jack for grounding of the tip at the front panel
of the station. This jack and other ESD items (wrist band
etc.) I normally connect to a standard ESD plug equipped
with a 1 MOhm resistor to the (yellow/green here in DL)
ground (Schutzleiter) of our 220V~ supply.
Now I had to replace the heating element of the WTCP-S and
soon after that the switch within the iron itself needs to
be replaced.
OK -- I think I'll replace the switch too but to have a
second iron available I found the WTCP 51 station which
seems to be the successor type using the same tips and
iron. Having good experiences with Weller and not enough
money to buy stations of JBS or even Metcall I want to
stay with them.

The tip is no longer connected to a front panel jack but
directly to the now three wire (two wires here at the
power supply of the WTCP-S) mains connection's ground of
the WTCP 51 station.

The question is:

Is it  better to insert a 1 MOhm resistor within the
station enclosure instead of this "hard" grounding?

But perhaps "Weller" had a good idea when connecting the
tip directly to ground and I only don't know it.

TNX, 73
Thomas, DF7TV

(We have a holiday here today and assembly of K2 #4138
can't continue...arrrrgh!)


--
Thomas Martin, Stuttgart, Germany
http://www.qsl.net/df7tv


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
http://mailman.qth.net/mailman/listinfo/elecraft
You must subscribe to post.
Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm
Elecraft page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

PA PROBLEM

EFMM
Hello to all:
My name is Eugenio and my call is EA7HG
I built a K2 (s/n4133),but i have high current (5A) when i Tx.
See on manual and say bad PA transistor.I change the 2X2SC1969 for others
new and have the same problem.
I need help.
Thank you all

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
http://mailman.qth.net/mailman/listinfo/elecraft
You must subscribe to post.
Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm
Elecraft page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Soldering Iron Weller WTCP-S / WTCP 51 tip groundingdirect or via 1MOhm res. ?

Stuart Rohre
In reply to this post by Thomas Martin-5
The Weller tip goes directly to AC power ground to meet UL and American
safety codes, (National Electrical Code)  Otherwise there is a shock hazard
if a shorted element contacts the sleeve.
-Stuart
K5KVH


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
http://mailman.qth.net/mailman/listinfo/elecraft
You must subscribe to post.
Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm
Elecraft page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: PA PROBLEM

Karl Larsen
In reply to this post by EFMM
On Thu, 10 Jun 2004, EFMM wrote:

> Hello to all:
> My name is Eugenio and my call is EA7HG
> I built a K2 (s/n4133),but i have high current (5A) when i Tx.
> See on manual and say bad PA transistor.I change the 2X2SC1969 for others
> new and have the same problem.
> I need help.

        Hi EFMM, please remove the 2x2SC1969 and then test without the
transistors. If the current is still 5A look for a short circuit around
the final transistors. If the current goes down to less than 1A look for
a wiring error in the transistor bias circuit.


> Thank you all
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> http://mailman.qth.net/mailman/listinfo/elecraft
> You must subscribe to post.
> Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm
> Elecraft page: http://www.elecraft.com
>

--
                     
               - Karl Larsen k5di Las Cruces,NM Az ScQRPions -

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
http://mailman.qth.net/mailman/listinfo/elecraft
You must subscribe to post.
Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm
Elecraft page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: PA PROBLEM

Don Wilhelm-2
In reply to this post by EFMM
Eugenio,

Try these steps first:

1) Measure the resistance between RF Board D9 (cathode end) and Control
Board MCU (U6) pin 2 - it should measure 3.45 ohms (or very close to that
value).  This verifies that the VRFDET signal can reach the MCU.  If you
find a much higher or lower resistance, find the fault first.

2) Check all toroids for the proper number of turns and well tinned, well
soldered leads (the solder joint should look like a mountain, but not a
volcano).  Particularly check T1, T2, T3 and T4.

3) Check all components for proper values and all diodes for proper
orientation.

4) Under a magnifying glass, check all soldering carefully, then recheck all
soldering, and finally, check all soldering.

Component failures are rare unless the components have been subjected to
abuse, so double-check all your work before concluding that a component has
failed.

73,
Don W3FPR

"Life is what happens when you are making other plans"
(John Lennon wrote it in a book, Mike Cross used it in a song - I don't know
who was first)

----- Original Message -----

> Hello to all:
> My name is Eugenio and my call is EA7HG
> I built a K2 (s/n4133),but i have high current (5A) when i Tx.
> See on manual and say bad PA transistor.I change the 2X2SC1969 for others
> new and have the same problem.
> I need help.
> Thank you all
>


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
http://mailman.qth.net/mailman/listinfo/elecraft
You must subscribe to post.
Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm
Elecraft page: http://www.elecraft.com

Loading...