【已解决】建武TS-50 PLL板CAR 10.69M信号输出电平不正常（ssb无接收） [复制链接]

已解决，传送门 http://www.hellocq.net/forum/read.php?tid=352999&ds=1&page=1&toread=1#tpc


得一台建武ts-50 原机电解电容、记忆电池均被前机主换新，ssb接收不正常，发射正常，s表指示正常。

经前期排查，现查出PLL板CAR端口10.69M信号电平不正常（LO1 LO2输出电平正常），用kc901s频谱模式测得为输出电平仅-17dbm左右，（维修手册标定值为-4dbm）偶尔机器接收正常时可测得为-3.75dbm，已尝试调换输出耦合电容c121、混频ic sn16913（ic7）、检查Q9/Q10工作点均无果，排查失去方向，查.net、.com、youtube、google均有相同故障现象，猜测均为10.69m信号电平过小导致，但未见维修后续，现向各位老师、前辈们请教排查思路和维修经验。

已自行修复，择日发帖

找不到病因无处下药:-(

内容来自[手机版]

BG7MI:找不到病因无处下药:-(
内容来自[手机版]  (2017-01-21 06:37) 

您也有这台机器吗？

雅虎上的相关帖子：  https://groups.yahoo.com/neo/groups/Kenwood_TS50/conversations/messages/4827  

似乎不少老外在骂TS-50的dds的问题
Eddie BrindleyOct 2, 2016
I have one with very low audio on SSB,am,fm ok.After it warms up maybe 20 minutes or 2 hrs. It's ok.This is before the audio amp input.

Sent from my iPad

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My TS50 has developed very noisy receive , especially on 80 and 40 meters. Sounds like heavy QRN static, but is present even when the antenna is disconnected.

Gordon VE3JSJ
有回帖建议补焊dds单元的电阻

Re: Noisy audio on receive
Clif HollandOct 3, 2016
On the low audio at turn on. Resolder the DDS resistor packs. Low Car
level causes low audio. If you have a 'scope the Car TP on the PLL unit
should have ~1.5v P-P

--
Clif Holland KA5IPF
www.avvid.com
214-850-0973

已自行修复，择日发帖

小朋友，你在班里学习成绩如何啊？年纪轻轻咋这么牛？