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Re: Does anyone know PIERRE EFKHANIAN ??

Heikki,

I think Pierre's call sign is F4DOE
I found this page http://hamcall.net/call/F4DOE
It needs registration to get more information.

73 Matti OH7SV
by OH7SV
05 Feb 2012 19:47
 
Forum: Juma Discussion
Topic: Does anyone know PIERRE EFKHANIAN ??
Replies: 1
Views: 2366

Re: TRX2 Spur Elimination Option

John,

Spur Elimination Option (JUMA TRX2 SE Option) has been added to Juma online shop www.nikkemedia.fi/juma/online-shop
See information of JUMA TRX2 SE Option www.nikkemedia.fi/juma-trx2/rev-b/juma- ... uction.pdf

73 Matti OH7SV
by OH7SV
24 Jan 2012 12:04
 
Forum: Juma Discussion
Topic: TRX2 Spur Elimination Option
Replies: 1
Views: 2191

Re: Flex1500 & PA100D auto band select

That's right Jari, JUMA PA100D model has a frequency sense function as an auto band selection alternative. PA100D detects the band from the RF signal coming from an exciter. The frequency sensing mode is set in CONFIG pages http://www.nikkemedia.fi/juma-pa100/pa100-buttons-description.html Other PA1...
by OH7SV
22 Jan 2012 18:47
 
Forum: Juma Discussion
Topic: PA100 and Flex 1500
Replies: 3
Views: 4347

Re: JUMA PA1000 Linear Amplifier

David,

Thanks for good comments.
I have noticed the Murata SMPS. They look good but are too big (long) in size to integrate in the enclosure.
Christi's resonant looks attractive. I might contact him for a custom model.

73 Matti OH7SV
by OH7SV
16 Jan 2012 11:04
 
Forum: Juma Discussion
Topic: JUMA PA1000 Linear Amplifier
Replies: 50
Views: 101787

Re: Juma TRX2 Firmware, Version 1.07u Build 12

Robert, The TRX2 firmware developed by Adrian can be found in TRX2 Technical kit information page http://www.nikkemedia.fi/juma-trx2/rev-b Down there is a link "User HW and SW modifications" http://www.nikkemedia.fi/juma-trx2/rev-b/JUMA-TRX2-user-modifications.html Open the firmware zip fi...
by OH7SV
11 Jan 2012 06:35
 
Forum: Juma Firmware by 5B4AIY
Topic: Juma TRX2 Firmware, Version 1.07u Build 12
Replies: 4
Views: 5902

Re: PA100 and Flex 1500

Gord,

5W drive power is enough for JUMA PA100 to get out 100W or even more.
The gain of PA100 can be adjusted by the means of the input attenuator.
This feature is in both models PA100 and PA100-D.

73 Matti OH7SV
by OH7SV
10 Jan 2012 16:19
 
Forum: Juma Discussion
Topic: PA100 and Flex 1500
Replies: 3
Views: 4347

Re: Juma TRX2A - Voltage supply problem in Main Board

Saku,

I think you found the main problem now :)
The OPAMPs A10 and A11 are installed 180 degrees in wrong position!
Remove them and check the +10V. If the voltage is ok you can try if those OPAMPs are still ok.

73 Matti OH7SV
by OH7SV
06 Jan 2012 21:21
 
Forum: Juma Discussion
Topic: Juma TRX2A - Voltage supply problem in Main Board
Replies: 17
Views: 15133

Re: TRX2A Power out falls off, Sub Harmonic.

Robert, The TRX2 rear panel has been changed to double sided PCB with thick copper layers abt one year ago. You can feel heat but that is ok because the final MOSFETs can easily handle the power dissipation although they are warm. 2 ea IRFI510 mosfets can dissipate more 40W at case temperature of 60...
by OH7SV
06 Jan 2012 19:25
 
Forum: Juma Discussion
Topic: TRX2A Power out falls off, Sub Harmonic.
Replies: 1
Views: 1872

Re: Juma TRX2A - Voltage supply problem in Main Board

Ok Saku, Let's continue with smaller steps. 1. I did not mean the RF Filter but the 1st AF filter which is plugged on the main board, marked FILTER1 on the PCB. Remove it and check if it helps with the +10V. 2. Is the +10V regulator REG2 getting hot when you keep power on for some time? 73 Matti OH7SV
by OH7SV
06 Jan 2012 14:55
 
Forum: Juma Discussion
Topic: Juma TRX2A - Voltage supply problem in Main Board
Replies: 17
Views: 15133

Re: JUMA PA1000 Linear Amplifier

Initial encouragement by Freescale in the choice of the device was strong but experience has revealed problematic levels of harmonic energy at the output. Freescale now acknowledge this problem to be significant when using these devices at HF. They have quoted H3 at -7dBc and H5 at -13dBc being the...
by OH7SV
04 Jan 2012 18:23
 
Forum: Juma Discussion
Topic: JUMA PA1000 Linear Amplifier
Replies: 50
Views: 101787
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