Page 5 of 6

Re: JUMA PA1000 Linear Amplifier

PostPosted: 16 Sep 2014 15:54
by KK3AN
Hello Gents,

A very interesting thread. Would there be any drain waveforms at 1.8, 14, 30 and 54MHz also available to see?

vy 73, Dan KK3AN

Re: JUMA PA1000 Linear Amplifier

PostPosted: 27 Jan 2015 09:12
by ok1rp
Hello,

is there any news regarding the Juma PA1000 or any update for this project please?

Kiitos teille,
Hei
73 - Petr, OK1RP

Re: JUMA PA1000 Linear Amplifier

PostPosted: 17 Feb 2015 10:22
by OH7SV
Petr and others,

See the update here http://www.jumaradio.com/juma-pa1000

73 Matti OH7SV

Re: JUMA PA1000 Linear Amplifier

PostPosted: 24 Oct 2015 22:34
by ok1rp
Hi
looks like still unavailable in eshop...
73 - Petr, OK1RP

Re: JUMA PA1000 Linear Amplifier

PostPosted: 06 Nov 2015 22:22
by ok1rp
Hi

is there fully working QSK implemented in Juma PA1000 please?

73 - Petr, OK1RP

Re: JUMA PA1000 Linear Amplifier

PostPosted: 01 Feb 2016 14:19
by ok1rp
...seems that no one knows...

Petr, ok1rp

Re: JUMA PA1000 Linear Amplifier

PostPosted: 04 Feb 2016 17:51
by OH7SV
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

Re: JUMA PA1000 Linear Amplifier

PostPosted: 09 Feb 2016 14:32
by ok1rp
Hi Matti,

thank you. So is it possible to use it in full and smooth QSK mode operation driven by PTT from Elecraft K3 for example please?

Thanks for reply.

73 - Petr, OK1RP

Re: JUMA PA1000 Linear Amplifier

PostPosted: 19 May 2016 20:10
by LU6PSG
Hello. I have been following this interesting thread, and I have to admit that this amplifier has amazed me.

The output transformer solution is wonderful, 2 transformers with paralelled secondary windings, overcoming the push-pull known problem described by Manfred Mornhinweg (ludens.cl).

However, I have seen a picture of the PA-1000 with a different transformer, one with a single ferrite bead and some sort of flexible copper tape as primary. Which transformer is the PA-1000 using at present , the parallel secondary with 4 ferrite beads or the single bead with copper tape primary winding ?

My personal opinion is that the copper tubing primary winding provides better coupling than a copper tape.

Image

73 DE LU6PSG

Re: JUMA PA1000 Linear Amplifier

PostPosted: 30 Jun 2016 18:02
by LU6PSG
Anyone ?