[TenTec] Jupiter 538 always on transmit

[F8EHJ]

Thanks for your reply,

I found the fault. I open the transceiver and verify voltage level on  
U9 from DSP Board.
It seems to be CW_KEY_T bad signal level '0' instead level '1'.
I measured 1,35 v on input buffer. Datasheet shows a VIL max of +1,8v  
typical.

I unplugged DSP board and verify diode, resistor. I think U9 is bad  
or  solder under pin.

I must unsolder U9 and I will post news about repair.

73's
Herve F8EHJ




Le 8 août 10 à 17:24, Rick W a écrit :

> Herve you may have already tired this BUT  the first thing I would  
> do is disconnect ALL cables to the rig except the power supply.   
> That includes, mic, CW key and any cables on the rear.  Turn on the  
> rig and see if it still goes into transmit.
>
> I do not have a ten-Tec Jupiter but If it still goes into transmit  
> it looks like the rig may be getting a "T" voltage from a source  
> and it may be a component failure in the transmit chain.
>
> Good luck.
>
>
> 73,
> Rick
> VE7TK
>
> Website: http://www.ve7tk.com
>
> To:	Discussion of Ten-Tec Equipment <tentec at contesting.com>
> Subject:	[TenTec] Jupiter 538 always on transmit
> From:	F8EHJ <f8ehj at free.fr>
> Reply-to:	Discussion of Ten-Tec Equipment <tentec at contesting.com>
> Date:	Sun, 8 Aug 2010 16:41:05 +0200
> List-post:	<tentec at contesting.com">mailto:tentec at contesting.com>
> Hello,
>
> After a long time  without radio operating (about 6 months), I wished
> to turn on my tansceiver Jupiter 538.
> When I powered on, the TT jupiter is always transmiting on Ham radio
> Band.
> I test all modes, bands, it is like the PTT or CW key are pushed.
> I performed a master reset (A CONTROL KEY PUSHED and POWER SWITCH
> TURNED ON) and downloaded lastest firmware version (1.32) without
> success.
> I tested with schematic help the input signals CW KEY (from jack on
> front panel) and PTT (from ACC1). They are no short circuited.
>
> Did  anyone have  this problem ?
>
> Best 73's
>
>
>
>