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Juma TX500

PostPosted: 06 Aug 2012 15:29
by dk1kq
Hi struggling with failure
on LCD Display "CURR" is blinking with short beeps.
What is causing this indication?
Uwe is asking
73

Re: Juma TX500

PostPosted: 10 Aug 2012 10:01
by dk1kq
This failure is caused by overcurrent.
(IC7 MAX 4373TESA) is generating FAULT. After removing Overcurrent it should generate Overcurrent RESET/not
(in my case it did not)

73
Uwe, DK1KQ

Re: Juma TX500 Terminal Programm ?

PostPosted: 10 Aug 2012 10:06
by dk1kq
In Order to programm the JUMA TX 500 ( Also TX 136) a Terminal programm is needed
Programming EEPROM
Dont have my old W98 anymore

What Terminal - Programm would work with XP or W7

I am not talking about the JUMA TX136 & TX500 control software !


73
Uwe

Re: Juma TX500 Terminal Programm ?

PostPosted: 08 Sep 2012 19:35
by rv3apm
dk1kq wrote:In Order to programm the JUMA TX 500 ( Also TX 136) a Terminal programm is needed
Programming EEPROM
Dont have my old W98 anymore

What Terminal - Programm would work with XP or W7

I am not talking about the JUMA TX136 & TX500 control software !


73
Uwe



I use on Windows 7 32 bit with success Hercules
http://www.hw-group.com/products/hercules/index_en.html
73 Serge

Re: Juma TX500

PostPosted: 09 Sep 2012 06:08
by 5B4AIY
I use a very simple terminal program, SimpleTerm, (ZIP attached.) It works with Win-XP, Win-Vista, and Win-7 in the latter case, both the 32-bit and 64-bit versions. It does not install anything, simply launch the executable. I have used this terminal program for all the firmware development I did for the Juma TRX-2 and PA-100D and it was more than adequate. When you launch it, select the COM port, the speed, and, in the case of the Juma serial ports, the default Flow Control is OK, set the Device Control to NO.
73, Adrian, 5B4AIY

Juma TX500 RX Converter

PostPosted: 10 Jan 2013 11:11
by dk1kq
In my new built JUMA TX 500 I run into Problem.
The RX Converter can be switch on / off.
But when I try to activate Pre- Amplifier Gain it switches directly to 20dB, because Hi- level coming from Controller as switched to 10db or 20 dB Gain.
Thats definitly wrong.
The Signal is comming from Pin 35 (Controller, Temp)
There is no short from pin 34 or 36 to pin 35.

Could it be a failure in Controller or software ?

In case of software- failure- how can I RESET all ?

Any hints welcome

Uwe, DK1KQ

Re: Juma TX500

PostPosted: 14 Jan 2013 01:37
by VE3GSO
An over current can only occur on transmit, because the current is monitored by R41 to the final transistors. Use a strong magnifying glass and check the traces and pads around Q8 and the two finals for solder shorts. The solder resist should prevent this but anything is possible. Also check the Tantalum Cap C49. They are 4.7uF 16V, which is a narrow margin when using a 14 volt supply.

After a bit of testing on the TX500 I still have on my bench I had an over current alarm moments after keying for the first time. I reset by switching off and on again. Shortly after that the 7.5A fuse blew. I found that both C49 and C60 had failed shorted. This with my supply at 13.55V. I love Tantalum caps for their small size and low leakage, but would design in a 25V cap for a 13.8 volt supply! So to be safe I also pulled out C43 and will replace with three new Tantalum caps from Digikey.

One design change I'd make to the TX500 kit would be to place another ground pad for each of these caps to allow for 25V caps, which are a bit longer.

Dave