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Topic Created Posts Views Last Activity
Kenwood tw-4000A where to begin Apr 5th, 17:34 2 266 on 6/4/20
NANOVNA SWR readings Nov 10th 2019, 17:19 2 2,120 on 12/11/19
Kenwood TW-4000A overheater? Aug 27th 2019, 20:46 3 1,064 on 28/8/19
power for Kenwood TW-4000A Aug 22nd 2019, 18:14 5 933 on 25/8/19

Latest Posts

Topic Author Posted On
Kenwood tw-4000A where to begin KN6CWJ on 5/4/20
Someone was going to throw away an old TW-4000A that was not working so I took it off his hand to see if I could make it work and learn something about ham radio and electronics in the process. I am using an power adapter with an output of +12V 3amps. My first challenge is the tuning dial does not function. The operator manual indicates that there is a D.Lock switch on the left side of the face plate. The switch in that position is noted as v.rcl. cannot find any reference in the doc that explains what it is. The frequencies that I can get are limited to what was stored in memory. Currently I am using the UHF side of the duel band radio. I am able pick up some transmissions but its drops before the transmission is completed. I configured my handheld to the same frequency, and it was able to send and receive. but I am not sure that I am sending anything out. Additional when I press the PTT the display goes out briefly and comes back on. I found instructions to reset the microprocessor by Shorting the 2P terminal, but it did not have any affect. There is a beeping tone that goes off about every 10 seconds. That’s it. Any thoughts?
NANOVNA SWR readings KN6CWJ on 10/11/19
I received my technicians license about a year ago and I'm studying for the general I currently have a Boefang HD UV 82HP(rookie mistake) an old kenwood-TW-4000 that someone gave me. But you should see my Christmas list. One area that have drawing my attention are types antennas and performance. I have read a lot of articles and bought a NanoVNA to measure the SWR on the HD antenna that I have. The scan provided me with some output, but I am not sure exactly how to interpret the findings. The forum doesn't provide a method to upload a file so I'll do my best to describe it. The S11 graph: Y axis (.09,1), X axis (140.0m,160m). The plot line was (.58,.26,.38). The S11 VSWR Y axis (1.0,4), the X axis was the same. Its plot was (3.73,1.60,2.39). The S11 return loss(db) graph Y axis (0,20) X axis the same. The loss plot, was (4.9,11,7.5). How do I go about interpreting the findings? I have already started to build a simple ground plane antenna but a need a reference point to understand the NanoVNA graphs as I try and tune it.
I hope this make sense to someone. Being so new that this it can get a bit frustration as I learn to walk in this new realm
Kenwood TW-4000A overheater? KN6CWJ on 28/8/19
Another success story. Thank you W1VT for pointing me in the right direction.
Kenwood TW-4000A overheater? KN6CWJ on 27/8/19
This is a continuation of my immersion in to ham radio and working with a very old Kenwood TW-4000a. With the assistance of member of the forum community I was able to power up the Kenwood and there were signs that it was working. Next with the assistance of others I built a 2-meter J-pole out of some copper left over from a bathroom remodel. Did not have any coax with the right connector so I disassemble an old CB radio antenna and connected it to the J pole. Much to my surprise when I fired it up and changing the antenna, I could receive transmissions from a repeater located about 40 miles away. I had setup the radio and antenna on our deck which turned out to be a bad idea. The temperature that afternoon around 95+ degree. Something must have fried. The Kenwood still had power but it no longer scanned and I could not manual change frequencies. I would get a repeating beep. I thought that if I disconnect everything and allow it to cool down it would reset itself. Unfortunately, it did not have any effect. I did a YouTube search that provide directions to disassemble the Kenwood and how to change the 3v battery. I have not put the Kenwood back together yet but I doubt that the battery could be the problem. I have been able to download the schematic. So, my question is if this is an overheating problem where would I begin to look. Using the schematic as a guide where should I begin my problem determination.
power for Kenwood TW-4000A KN6CWJ on 25/8/19
Got It. Thanks

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