Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Installing TU-4c in TW-4000A  (Read 4442 times)
G8ANT
Member

Posts: 7




Ignore
« on: March 06, 2013, 05:03:41 AM »

Have just obtained a TU-4c CTCSS module for my TW-4000a which currently has the 1750Hz board installed.

I had foolishly assumed it would be a straight swap until I discovered that the TU-4c has a 4 pin connector while the 1750 Hz module has a 5 pin connector. The 1750 Hz module only uses pin 1 (tone), pin 2 (Earth) and Pin 3 (EB). I guess there is only one pin because the same tone is used on both 2m and 70cms.

The TU-4c has pin 1 (tone), pin 2 (earth), pin 3 (EB4)(70cms) and pin 4 (EB1)(2m).  I can overcome the problem of the connector size by hard wiring but how do I make the connections to EB1 and EB4?

Thanks.

Simon
Logged
W9GB
Member

Posts: 2623




Ignore
« Reply #1 on: March 06, 2013, 03:13:25 PM »

Earlier eHam.net question (2012)
http://www.eham.net/ehamforum/smf/index.php?topic=82190.0

There is a YouTube video (9 minutes) that demonstrates proper installation of TU-4C.
You can contact Kenwood Europe, IF Europe had a different TW-4000A model.

LOOK CAREFULLY for a FOUR PIN (loose cable connector) in harness on bottom of radio.
DIP Switches accessible from bottom of radio, when properly installed.
http://elektrotanya.com/kenwood_tu4a_tu-4b_tu-4c_sch.pdf/download.html

Kenwood TW-4000A Instruction / Owner's Manual
http://ftp.qrz.ru/pub/hamradio/schemes/kenwood/TW-4000A_Instruction_manual.pdf

Kenwood TW-4000A Schematic Diagram
http://www.radiomanual.info/schemi/TW4000_sch.pdf

FIND a copy of the Kenwood TW-4000A SERVICE MANUAL.
Page 39 covers the TU-4c CTCSS installation.
http://marketplaceadvisor.channeladvisor.com/StoreFrontProfiles/DeluxeSFItemDetail.aspx?sid=1&sfid=86409&c=15468&i=196653886

Settings on TU-4c CTCSS module
http://www.universal-radio.com/catalog/fm_txvrs/tu4c.html
DIP Switches
http://www.qsl.net/w/wb4kdi/Kenwood/TW-4000A/tu-4c_settings.gif
« Last Edit: March 06, 2013, 03:45:23 PM by W9GB » Logged
G8ANT
Member

Posts: 7




Ignore
« Reply #2 on: March 06, 2013, 11:40:34 PM »

Thanks for the extensive reply. I already have most of the documentation you mention with the exception of the Service Manual (although I have the schematics for both the TW-4000A and TU-4c). The problem, as I said, is that the only connector in the bottom of my TW-400A is a 5 pin connector currently plugged into the 1750Hz tone unit (type X52-1250-50).

I guess there are a number of variations of this modle  - all mine says on the case is TW-4000A
Logged
W9GB
Member

Posts: 2623




Ignore
« Reply #3 on: March 07, 2013, 07:11:32 AM »

Yes, I saw the 5-pin on the schematic diagram,
with the Tone-Burst (1750 Hz) option using the NE555 IC.
The first 3 pin assignments on the connector match the TU-4c, IF correctly installed.
A DVM or VOM can quickly confirm.


The Kenwood TU-4c, according to schematic, uses the MX315 IC
http://www.datasheetcatalog.org/datasheets2/17/179186_1.pdf

LOOKING at the TU-4c schematic, you see that PIN 14 of the MX315 receives VDC for power.
The power is on 2 pins ... One for VHF, the other for UHF DIP switches.
The 2 other lines are for E (Earth, Ground) from pin 7 and T (CTCSS tone output) from pin 11
http://elektrotanya.com/kenwood_tu4a_tu-4b_tu-4c_sch.pdf/download.html

The YouTube video clearly shows a 4-pin connector ...
so different regional models may exist ... OR production change.
« Last Edit: March 07, 2013, 07:25:48 AM by W9GB » Logged
G8ANT
Member

Posts: 7




Ignore
« Reply #4 on: March 07, 2013, 09:46:28 AM »

Thanks for the additional information.

I have cut off pin 5 of the plug so it fits the TU-4c which means power (pin 3) goes to EB4 and no connection is made to EB1 (pin 4). Strangely, it works on 2m and I can trigger local repeaters but I am not able to trigger repeaters on 70cm using the same CTCSS frequencies.

Oh well, keep persevering!
Logged
W9GB
Member

Posts: 2623




Ignore
« Reply #5 on: March 07, 2013, 11:17:44 AM »

I was trying to explain to you that DC power for VHF and UHF are SEPERATE, as shown in the Kenwood TU-4c.  Which means you will have 2 DC sources on the plug, depending if VHF or UHF mode is selected!

BTW, while you cut wire for pin 5 .... did you even bother measure with a VOM?  OR to trace it to source in radio?
Logged
G8ANT
Member

Posts: 7




Ignore
« Reply #6 on: March 07, 2013, 02:07:59 PM »

There is no connection to Pins 4 and 5 in my TW=4000A  - my quote "The 1750 Hz module only uses pin 1 (tone), pin 2 (Earth) and Pin 3 (EB). I guess there is only one pin because the same tone is used on both 2m and 70cms."

The lead to the tone module only has 3 leads - Pin 1 Tone output that feeds to the mic amplifier; pin 2 earth and pin 3 that links to the tone switch on the front panel.
Logged
W9GB
Member

Posts: 2623




Ignore
« Reply #7 on: March 07, 2013, 02:39:42 PM »

YouTube video of TU-4c module installation in Kenwood TW-4000a
http://www.youtube.com/watch?v=z06F9IQrceo
« Last Edit: March 07, 2013, 02:53:35 PM by W9GB » Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!