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Recommended TRX2A modification

In some TRX2A units the GAIN BLOCK A9 on the Main Board can be overdriven which may cause splatter. To avoid possible splatter there is an easy modification by adding one resistor and one capacitor to the unused pads on the All Band PA Board. This modification increases the PA gain and thus gives mo...
by OH7SV
13 Dec 2014 09:06
 
Forum: Juma Discussion
Topic: Recommended TRX2A modification
Replies: 0
Views: 3937

Re: TX136/500 QRSS and DFCW modes added

Patrick,

Great work! DFCW has been requested many times for TX136 and TX500.
Thank you very much.

73 Matti OH7SV
by OH7SV
03 Sep 2014 09:23
 
Forum: Juma Discussion
Topic: TX136/500 QRSS and DFCW modes added
Replies: 7
Views: 13578

Re: Sticky Pen for SMD and tiny parts assembly and handling

Petr,

Sticky Pen looks clever tool for SMD. Where did you get those pens?

73 Matti OH7SV
by OH7SV
25 Aug 2014 08:57
 
Forum: Juma Discussion
Topic: Sticky Pen for SMD and tiny parts assembly and handling
Replies: 5
Views: 8690

Re: JUMA PA1000 - update?

Have a look on JUMA PA1000 update www.jumaradio.com/juma-pa1000/

73 Matti OH7SV
by OH7SV
24 Aug 2014 22:00
 
Forum: Juma Discussion
Topic: JUMA PA1000 - update?
Replies: 1
Views: 3860

Re: JUMA Kits Availability

Good news!

The first JUMA kits are now available from new supplier OHKits (Yrjo OH3YP).
See Juma Shop http://www.jumaradio.com/shop

73 Matti OH7SV
by OH7SV
11 Apr 2014 15:05
 
Forum: Juma Discussion
Topic: JUMA Kits Availability
Replies: 3
Views: 6583

JUMA Kits Availability

Good news to all,

The most popular Juma kits will be available soon. The new supplier Yrjo OH3YP has been working hard. The first kits will be available soon, keep watching Juma Shop.

73 Matti OH7SV
by OH7SV
27 Mar 2014 18:04
 
Forum: Juma Discussion
Topic: JUMA Kits Availability
Replies: 3
Views: 6583

Re: TX500 tx output, Missing signal Pin 76

Alex,

If the CW keyer is working and TX500 is in TX state the processor pin 76 should be going high/low as keying signal.
Is the CW keyer working?

73 Matti OH7SV
by OH7SV
25 Jan 2013 08:31
 
Forum: Juma Discussion
Topic: TX500 tx output, Missing signal Pin 76
Replies: 2
Views: 4901

Re: TRX1 PA Board

Marc,

The 2.5k high value is ok because there are 3 trimmers and other components in parallel.

Pse check your ohmmeter by shorting the meter wires. It should show zero to few ohms. If you have got a low ohmic resistor e.g. 100 ohms, test your ohmmeter with that too.

73 Matti OH7SV
by OH7SV
23 Nov 2012 07:16
 
Forum: Juma Discussion
Topic: TRX1 PA Board
Replies: 10
Views: 11803

Re: TRX1 PA Board Bias adjustment

Marc, There must be some very simple silly mistake in your measurement because this should be very easy to measure. The bias trimmer pots are 10 kohm trimmers and typically they will go clearly below 100 ohms at both end when turning fully to corresponding direction. Let's start from the beginning a...
by OH7SV
22 Nov 2012 18:51
 
Forum: Juma Discussion
Topic: TRX1 PA Board
Replies: 10
Views: 11803

Re: TRX1 PA Board

Marc,

They should go lower. Are you sure that you are measuring from gates?
Maybe it is easier to locate the trimmers center leg. Pse measure resistance directly from trimmers center leg to GND and turn the trimmers to minimum ohms reading.

73 Matti OH7SV
by OH7SV
22 Nov 2012 16:26
 
Forum: Juma Discussion
Topic: TRX1 PA Board
Replies: 10
Views: 11803
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