Mark, those resistors serve no other purpose than to provide current limiting
for Q1 and Q2, which drive the slow speed motor for direction control. These
transistors are small signal to92 type rated for 1 amp each. The only way these
could be burning up as you say would be for two things to happen, 1: there is
something binding in the direction indicator, either with the motor itself or
the associated direction potentiometer VR2 and this is causing the motor to
draw excess current, or 2: the actual motor is drawing excessive current and is
causing the resistors to drop excessive voltage/current thru them. It's
possible that the motor is under-rated for the current that it needs, but
highly unlikely, as the 800S, 800 SDX, 1000S, 1000SDX, and 2800SDX utilize the
same basic circuitry for direction indication and again, I have never heard of
this problem on any of these rotors, which we have sold many of so far.
I would scope the input leads for stray rf coming into the box, and/or put an
ammeter on the actual direction motor leads and verify what the current is that
it is drawing, and go from there.
If you get really unhappy with it, send it to me and i'll make good use of it
for you. :)
I cc'ed the reflector on this as it may be useful information for others.
Scott
KA1CLX
At 11:59 AM 2/15/99 -0600, you wrote:
>Hi Scott
> R2 & R3 which are on the outputs of the transistors that
>feed the direction indicating motor. I talked to Yaesu tech
>support & was told to ship them the control box because it
>is to complicated for anyone else to fix (gee I've only been
>fixing consumer electronics & pc's for 20 years & I told
>tech support that). I give up on this thing, it has been a
>piece of garbage from day 1.
> Mark
>
>
>Scott Bullock wrote:
>>
>> Mark, I find it hard to believe, as we have sold these for 2 years and not
>> experienced these problems. Why don't you talk to Yaesu tech support and try
>> and figure out what is causing these resistors to heat up and burn out? The
>> traces on the board are obviously burning out due to excessive current from
>> too big a sized resistor being installed. But what is causing all this
>> current? Something doesn't sound right. What are you turning with it?
>> Which resistors are burning out, i'll look at our service manuals on it and
>> see what I can find out for you.
>> Scott
>> KA1CLX
>>
>> At 10:57 PM 2/14/99 -0600, you wrote:
>> >
>> >Hi All Again
>> > Just replaced the 2 resistors in the control box of the
>> >g800 AGAIN, this time with 120 ohm 2 watters, if they go I
>> >am going to chuck this piece of s__t out the door & put up
>> >the ham 4.
>> > Mark
>> >ps:the last set of 120ohm 1 watters lasted less than 2
>> >weeks, Yaesu claims their aren't any problems with the
>> >design of the g800s control box, the first set of resistors
>> >died at 3 months (they supplied replacements) the second at
>> >13 months (send it in we will fix it for around $100), this
>> >is now the 6th pair of resistors & the control board has
>> >burnt through so bad that I have had to replace traces with
>> >wire! The g800s control box is JUNK!!!
>> >
>> >Douglas Bradford wrote:
>> >>
>> >> Andy Wallace wrote:
>> >> >
>> >> > Steve--
>> >> >
>> >> > The clutch would only let loose in dangerously high winds. I'd rather
>> >> > replace a
>> >> > coax connection then worry with a tower twisted down--I think it would
>> >> > be a
>> >> > little cheaper.
>> >> >
>> >> > Andy K5VM
>> >>
>> >> If the wind is high enough to twist the Tower, I would think everything
>> >> else would be gone. You are speaking of Tornado type wind.
>> >>
>> >> 73 Brad KZ5Q
>> >>
>> >> --
>> >> FAQ on WWW: http://www.contesting.com/towertalkfaq.html
>> >> Submissions: towertalk@contesting.com
>> >> Administrative requests: towertalk-REQUEST@contesting.com
>> >> Problems: owner-towertalk@contesting.com
>> >> Search: http://www.contesting.com/km9p/search.htm
>> >
>> >--
>> >FAQ on WWW: http://www.contesting.com/towertalkfaq.html
>> >Submissions: towertalk@contesting.com
>> >Administrative requests: towertalk-REQUEST@contesting.com
>> >Problems: owner-towertalk@contesting.com
>> >Search: http://www.contesting.com/km9p/search.htm
>> >
>> >
>> >
>>
>> Advantage Communications
>> Professional Wireless Communications
>> www.advantagecomm.net
>> 978-568-1944
>
>
<bold><bigger>
Advantage Communications
</bigger></bold>Professional Wireless Communications
www.advantagecomm.net
978-568-1944
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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