JUMA PA1000 Linear Amplifier

[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

[ok1rp]

Hello,

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

Kiitos teille,
Hei
73 - Petr, OK1RP

[OH7SV]

Petr and others,

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

73 Matti OH7SV

[ok1rp]

Hi
looks like still unavailable in eshop...
73 - Petr, OK1RP

[ok1rp]

Hi

is there fully working QSK implemented in Juma PA1000 please?

73 - Petr, OK1RP

[ok1rp]

...seems that no one knows...

Petr, ok1rp

[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

[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

[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.



73 DE LU6PSG

[LU6PSG]

Anyone ?