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Re: Improving cooling of JUMA PA100-D

Ok Roland,

Please check that the fan is blowing towards the heatsink! (Not sucking)
How was the original fan installed?

73 Matti OH7SV
by OH7SV
05 Jan 2018 10:34
 
Forum: Juma Discussion
Topic: Improving cooling of JUMA PA100-D
Replies: 10
Views: 16903

Re: PCB Gerber files for the retired Juma kits

Here are few decent PCB suppliers and you can easily find more by Googling.

www.pcbway.com
www.pcbgogo.com
www.pcbcart.com

73 Matti OH7SV
by OH7SV
04 Jan 2018 19:08
 
Forum: Juma Discussion
Topic: PCB Gerber files for the retired Juma kits
Replies: 2
Views: 5011

PCB Gerber files for the retired Juma kits

Hello all, We have published the PCB Gerber files for the following retired Juma kits - RX1 Receiver - TX1 Transmitter - TRX1 Transceiver - TRX2-VM Voice Memory option - JUMA KB1 External Keyboard option Feel free to use these Gerber files for club projects or for your personal use. You can find the...
by OH7SV
04 Jan 2018 17:26
 
Forum: Juma Discussion
Topic: PCB Gerber files for the retired Juma kits
Replies: 2
Views: 5011

Re: Improving cooling of JUMA PA100-D

Roland, You are right that digi modes load more and especially if the 'keydown' transmit period is long the temperature will increase. Good news is that we have not heard any PA transistor failures in JUMA PA100-D. There is one very easy improvement for additional cooling. See the section 3. in the ...
by OH7SV
01 Jan 2018 15:50
 
Forum: Juma Discussion
Topic: Improving cooling of JUMA PA100-D
Replies: 10
Views: 16903

Re: TX 500 Filter orientation

Mike and others,

T1, T2, T3 and T4 are symmetrical RF transformers so you can install them in the two orientation.

The SWR bridge transformers T5 and T6 are not symmetrical but the PCB routing is designed so that you can install them also in the two orientation.

73 Matti OH7SV
by OH7SV
21 Dec 2017 19:47
 
Forum: Juma Discussion
Topic: TX 500 Filter orientation
Replies: 2
Views: 4446

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: 9068

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: 9068

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: 9068

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: 3879

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: 5436
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