TS-440S TX meter full pegged!

Discussion in 'Radio Circuits, Repair & Performance' started by AE4LH, Jun 27, 2021.

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  1. AE4LH

    AE4LH Ham Member QRZ Page

    Hello. I have a TS-440S that has been in storage for 10 years. I took it out yesterday (at Field Day), connected it up, and the display was scrambled. I did a reset (hold A=B and turned on the radio). The display came on nicely to 14.000, it looked perfect, but the transmit meter was fully pegged to the right. I did not have a mic plugged in, so I connected the mic and tried again. Same situation. What might be a solution I can try at home? Thank you for reading, and for idea and suggestions. vy 73 de David AE4LH
  2. AE4LH

    AE4LH Ham Member QRZ Page

    Hi, again! Of course, after posting my request, I have found my answer. I had the RF turned counter-clockwise. It needed to be fully clockwise. So, it's back to Field Day to see if I can put my old radio back on the air! I'd still like to change the internal backup battery. A YouTube video shows that it is a detail oriented job. I have a PDF copy of the service manual, so I will need to read that -- a few times -- before attempting. Again, thanks for reading. -= David =-
    W2VW likes this.
  3. KK4NSF

    KK4NSF Ham Member QRZ Page

    I run a TS-440s, and a few suggestions to try before you do anything inside the radio.

    1- check all of the settings..... make sure the antenna tuner button (if it has one) is not pressed. Make sure the black switch on the top is not set to VOX. Check the RF Gain and make sure it's on full gain. Make sure the meter switch is set to POWER, not swr.... and so forth. 90% of the time, the tuner button is the problem.

    2- IF the above fails, you'll have to open the radio up and check a few things..... especially look at the small co-ax cables near the finals. If they are loose or corroded, they'll cause that problem. To help you, here is a link to the service manual: https://erikarn.github.io/kenwood/TS-440/TS-440S_service_manual.pdf
  4. AE4LH

    AE4LH Ham Member QRZ Page

    Thank you for your helpful response. Great to have the link for the service manual. I'd saved it to PDF before putting the radio in storage 10 years ago. I hope you're having fun on Field Day.
    KK4NSF likes this.
  5. WA9SVD

    WA9SVD Ham Member QRZ Page

    Not sure about that particular model, but similar age Kenwoods (TS-140, TS-680, TS=790) used a somewhat unusual "CR2430" battery, with solder tabs:(. Watch the "Yoo Toob" or other videos, several times, if necessary. The TS680 was fairly simple as just the lower part of the case needs to be removed. I CAREFULLY (VERY carefully:rolleyes:) removed the old battery by prying off the solder tabs first. (Fortunately, even after 25 years, it had NOT leaked!) I will replace the original battery with a like CR2430, as soon as Amazon delivers the appropriate coin cell holders, and use soldered leads so replacement in the future will be simpler. Some have opted to forgo the original battery type, and go wit a CR 2032 battery, ubiquitous as back-up in most computers, and use pig leads to make the connection from a proper sized coin cell holder. There isn't all THAT much difference in capacity between the two battery types, but like suggested by Kenwood, FIVE years should be the expected life, (NOT 25 years!) My Kenwood TM3530, an even older vintage radio, actually used a CR2032 battery, but I installed a coin cell holder with soldered on leads, rather than trying to find (a more $$) battery with solder tabs already attached. Kenwood apparently responded to complaints, and newer radios, such as the TS-570 has the CR2032 in a holder (NO soldering or solder tabs needed:D) so replacement is no more a hassle than replacing the battery in a watch.

    Whatever you do, DO NOT try to solder directly to the battery, (regardless of what others may claim) as that can lead to failure/destruction of the battery, or weaken the delicate seals, and cause the battery to leak well before its time.
    AE4LH likes this.
  6. AE4LH

    AE4LH Ham Member QRZ Page

    Thank you for the great advice! Yes, I had watched a YouTube video with a description of soldering directly to the battery. I had not thought about installing a coin cell holder.

    I hope you had a nice Independence Day weekend.

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