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Re: PA1000 and Elecraft K3

Linas, I talked also to Juha OH2N who is an experienced K3 user. Juha suspected the power ON/OFF function thru the DB15 connector. According to Juha's foundings there has sometimes been problems with the related connections inside K3. Anyway I suggest that you make a GND wire between K3 to PA1000 gr...
by OH7SV
08 May 2017 19:46
 
Forum: Juma Discussion
Topic: PA1000 and Elecraft K3
Replies: 8
Views: 874

Re: PA1000 and Elecraft K3

Linas, Pasi is using a similar cable from K3 DB15 connector to PA1000 DB9 connector. Here are some additional tips: 1. Check again very carefully the K3 side connector solderings. The pins of DB15 connector are so near each others. Use some magnifier glass to see any possible shorts to near by pins....
by OH7SV
08 May 2017 10:26
 
Forum: Juma Discussion
Topic: PA1000 and Elecraft K3
Replies: 8
Views: 874

Re: PA1000 and Elecraft K3

Hello Linas, Nice to hear that your JUMA PA1000 is working fine :) You seems to be using the BCD band data/PTT cable illustrated in PA1000 user manual page 10, totally 6 wires. The four BCDx (BANDx) signals are pulled up to +5V with 100k resistors in PA1000. The PTT (KEYOUT-LP) is pulled up to +5V w...
by OH7SV
07 May 2017 18:52
 
Forum: Juma Discussion
Topic: PA1000 and Elecraft K3
Replies: 8
Views: 874

Re: No suppression of sidebands TRX2

Don, Good to hear that you found the problem :) Those 'dry' solderings are qute very typical. I recommend to use more time during soldering. The components can stand lot of heat. Ps. You can fine tune the opposite side band attenuation with the I/Q trimmer R42 on DDS board http://www.jumaradio.com/j...
by OH7SV
08 Aug 2016 19:31
 
Forum: Juma Discussion
Topic: No suppression of sidebands TRX2
Replies: 1
Views: 838

Re: Need TX500/136 or TRX2 Controller

Very good John,

Enjoy using your Juma.

73 Matti OH7SV
by OH7SV
11 Jul 2016 18:45
 
Forum: Juma Discussion
Topic: Need TX500/136 or TRX2 Controller
Replies: 4
Views: 936

Re: Need TX500/136 or TRX2 Controller

John,

Do you mean TX500/136 or PA100-D control board because the hardware of those are identical?
(TRX2 control board is different)

73 Matti OH7SV
by OH7SV
27 Jun 2016 17:14
 
Forum: Juma Discussion
Topic: Need TX500/136 or TRX2 Controller
Replies: 4
Views: 936

Re: JUMA PA1000 Linear Amplifier

Hello Petr,

JUMA PA1000 is using quite a fast and quiet mechanical T/R relay with max Operate/Release times of 4ms/6ms. That means you can implement quite a fast QSK but it is recommended to configure TRCVR "TXon" timing so that the relay is closed before transmit.

73 Matti OH7SV
by OH7SV
04 Feb 2016 17:51
 
Forum: Juma Discussion
Topic: JUMA PA1000 Linear Amplifier
Replies: 50
Views: 86386

More JUMA kits available now

Hello Juma friends,

There are now more kits available in Juma Shop, also the analog PA100 model.
Have a look www.jumaradio.com/shop

73 Matti OH7SV
by OH7SV
25 Dec 2015 22:10
 
Forum: Juma Discussion
Topic: More JUMA kits available now
Replies: 3
Views: 1683

Re: Juma TRX2A Info Needed Before Purchasing

Laurent, Thanks for your comments. Here are some preliminary good news. We have just completed the design and test of a new enhanced JUMA roofing filter FL2 option for TRX2. The standard roofing filter is using 3rd/5th order topology and the new enhanced filter option is using a carefully designed 9...
by OH7SV
20 Dec 2015 17:33
 
Forum: Juma Discussion
Topic: Juma TRX2A Info Needed Before Purchasing
Replies: 6
Views: 3075

Re: Juma TRX2A Info Needed Before Purchasing

Adrian, Thank you very much for your comprehensive answer. I have only two minor additions to your answer. 1. The Spurious Elimination Option (SE-option) is currently included in TRX2A kit package. 2. I am personally using only JUMA TRX2A and I have never lost a DX due to the TRX2A RX performance. S...
by OH7SV
16 Dec 2015 17:22
 
Forum: Juma Discussion
Topic: Juma TRX2A Info Needed Before Purchasing
Replies: 6
Views: 3075
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