Dc-dc 45-390v psu?

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Sa2clc
Posts: 6
Joined: 09 Feb 2020, 10:52

Dc-dc 45-390v psu?

Post by Sa2clc »

Has anyone tried the DC step up regulators available on ebay for powering the paraset and tube equipment like it?
Claims to be able to deliver 70w (although thats probably asking too much from it).
Audio guys use it with ok results.
Anyone?
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Parasetguy
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Posts: 49
Joined: 21 Aug 2018, 15:32
Location: The Netherlands, Velp
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Re: Dc-dc 45-390v psu?

Post by Parasetguy »

No experience with them. Are they HF-stable? What is the own power consumption of the step up regulator?
Look at Banggood.com for the same unit.

Cheers, Henk - Parasetguy
DJ5RE
Posts: 5
Joined: 23 Aug 2018, 18:07

Re: Dc-dc 45-390v psu?

Post by DJ5RE »

If you plan to use those fixed value modules be sure they are "isolated". I use 1W Modules, 12V to 24V in my Mk XXI. The current is limited to 42mA. See www.qrz.com/db/dj5re and scroll down to see the MK XXI. With 6x 24V I run the transmitter....
If you choose 12V/12V versions, the current is 84 mA max. But you need a lot of modules, each 6.- Euro....not a cheap solution!
BTW: This modules are great to power receivers, too. No noise from the "switching mode" detected so far. My Fu H.E.c is powerded by 4 of them is series, with 12V lead battery on the primary.
Sa2clc
Posts: 6
Joined: 09 Feb 2020, 10:52

Re: Dc-dc 45-390v psu?

Post by Sa2clc »

Well, found a local seller who carried the 390 volt modules, tested it to power the paraset, and it does work with no problems at supplying power the transmitter neither. There was hovewer some noise on the receiver, not sure though if that came from the power supply.
I already had a vibrator transformer and wanted to put that to use, so I ended up making a 4047-irf520 vibrator power supply, with integrated crystal "spot" oscillator.
In my swedish RA200, I use a switching psu module to power the filaments. No issues with noise on the receiver with that one.
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DJ5RE
Posts: 5
Joined: 23 Aug 2018, 18:07

Re: Dc-dc 45-390v psu?

Post by DJ5RE »

Hi everybody,

I had this 70W modules in focus for a while. The first test showed, that the massive changes in load using morse code is not good for them. They are very stable, nearly no voltage drop, but regulation is too slow. I got often unproper oscillation when pressing the key. Now I added a Pi.-Filter at the output: 22uF, 4,5 Hy (130 Ohms DC),220uF. CW is very fine now, it is 100% ok for transmitting. Although good RF filtering I was not able to get the noise out of the receiver. The inverter creates a lot of noise on receiving. So I can say, that these modules from China are NOT a substitude for a paraset power supply. I will use it for the CMS. Here, the receiver is running on batteries (1T4 valves), and only the transmitter (6V6....6L6 MOPA) needs the power from 12V generated by this inverter. see www.qrz.com/db/dj5re
Sorry, I can't offer a plug-and play solution for field-use of the paraset.
Tom, DJ5RE
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