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KG4OJN
06-30-2002, 03:35 PM
I'm having a problem in the 70cm band with my Ft-100D. The problem arises when I press the ptt on any frequency within the 70cm band. Sometimes I have to press the ptt 4-5 maybe 6 times to be able to get a low SWR. The antenna is working fine (X-50A Diamond). Also, the radio and componets are all grounded. If any fellow ham has any suggestions as to what the problem may be, please e-mail me at rtrg@ureach.com. #Thanks in advance for your help!

73 de KG4OJN
Rodolfo

K9STH
06-30-2002, 03:58 PM
What are you using to read SWR?

This sounds more like an SWR meter problem unless you have a dirty relay or something like that. You also should check the coaxial cable connections to make sure that they are "solid".

Glen, K9STH

NE5U
07-14-2002, 06:01 PM
I need to look for the link, but I remember that there is something about an internal grounding problem that can cause the SWR meter on the FT100D to indicate incorrectly.

Found the link: Yeasu FT100 FAQ (http://www.k0lee.com/ft100faq.html)

Go to the factory mods section and it will say this:

Intermittent High SWR ICON

Some owners have had trouble with the HIGH SWR Icon appearing while attempting to transmit on certain bands. The most common advice is to make sure that the antenna mount and radio are properly grounded via some heavy braided material to the vehicle chassis. Some owners have had success in using clamp-on ferrites with the separation kit cable wrapped several times around the ferrite to block common mode current from getting back into the rig. Ten meters seems particularly prone to the problem. Changing the feedline length has also helped in some cases, but this seems to move the problem around more than solving it at the root cause. Also, some owners have found that fixing the grounding of the LPF board by adding solder around the screw holes and in some cases tightening the screws or adding star washers was sufficient to make their grounding problems go away.

However, there is a very effective modification that has worked in every case. The mod involves fixing the grounding in the coax sockets on LPF of the radio and a metal shield on the Main Unit. A degradation in the LPF grounding can cause the rig to break into oscillation (even at lower power) causing the HIGH SWR icon to appear intermittently even with a good antenna match on the higher HF bands. The mod will eliminate this oscillation and the high SWR reports. Here is a page with links you can follow to several high resolutions pictures of the factory installed mod. The adhesive copper tape has been replaced screws or clamps that are attached to the casting web.

The SWR icon with an 'X' next to it indicates that the SWR is out of range. If you see an SWR icon with an 'O' next to it flash momentarily, it is an indication that the antenna has finished tuning and the SWR is 'OK'.


I've found this FAQ page to be very helpful.

73

Mike



WM5LL

NE5U
07-16-2002, 12:17 AM
Nope, it's an FT-100D problem that is cured with the factory mod. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

73

Mike
WM5LL

NE5U
07-16-2002, 12:19 AM
See-

FT100D

The FT100D is an updated version of the original FT100 that includes the following changes: It has a larger built-in speaker, a high stability crystal oscillator, a 500 Hz CW filter, and a CTCSS decoder. All of these features except the speaker were previously available as field-updateable accessories to the FT100. The FT100D was announced in May, 2000 and is currently shipping.
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Intermittent High SWR ICON

Some owners have had trouble with the HIGH SWR Icon appearing while attempting to transmit on certain bands. The most common advice is to make sure that the antenna mount and radio are properly grounded via some heavy braided material to the vehicle chassis. Some owners have had success in using clamp-on ferrites with the separation kit cable wrapped several times around the ferrite to block common mode current from getting back into the rig. Ten meters seems particularly prone to the problem. Changing the feedline length has also helped in some cases, but this seems to move the problem around more than solving it at the root cause. Also, some owners have found that fixing the grounding of the LPF board by adding solder around the screw holes and in some cases tightening the screws or adding star washers was sufficient to make their grounding problems go away.

However, there is a very effective modification that has worked in every case. The mod involves fixing the grounding in the coax sockets on LPF of the radio and a metal shield on the Main Unit. A degradation in the LPF grounding can cause the rig to break into oscillation (even at lower power) causing the HIGH SWR icon to appear intermittently even with a good antenna match on the higher HF bands. The mod will eliminate this oscillation and the high SWR reports. Here is a page with links you can follow to several high resolutions pictures of the factory installed mod. The adhesive copper tape has been replaced screws or clamps that are attached to the casting web.

The SWR icon with an 'X' next to it indicates that the SWR is out of range. If you see an SWR icon with an 'O' next to it flash momentarily, it is an indication that the antenna has finished tuning and the SWR is 'OK'.

Mike
WM5LL

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