Re: back on QRP on 23 cms again


Adrian G4UVZ
 

Might be wort contacting your electricity provider ..Western Power Distribution here in the SW.

I had intermittent tripping of my 4KW solar system a few years ago...they put in monitoring for a week then moved me onto another phase ..re-crimping the joints etc..easier to achieve in the countryside where we are fed overhead rather than under ground.
Additionally you could get an idea of your supply impedance either tuning on the solar system when it is producing 3+KW ...or probably more achievable, switch a 4 KW load on and off and record the volt drop. One further point, the waveform from your Solar will not be a perfect sine wave which could confuse your metering!

Best 73 Adrian

----Original message----
From : john@g8seq.com
Date : 18/11/2018 - 12:56 (GMTST)
To : UKMicrowaves@groups.io
Subject : Re: [UKMicrowaves] back on QRP on 23 cms again

Years ago I worked for Parmeko. We used to manufacture devices called line conditioners. One type used a thing called a constant voltage transformer the other type used triacs to switch in/out tappings on the transformer. I may still have one in the loft/garage, but I've got a feeling I gave it away a few years ago.

de John G8SEQ

-------Original Message-------
From: Richard <richard@g8jvm.com>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] back on QRP on 23 cms again
Sent: Nov 18 '18 12:48

Hi Andy
There are 3 as far as I know, the street runs north -south, so most of
the fitted panels tend to be on extensions, or where the houses are
set back .
I've panels on both sides of the roof , which seems to work well , its
a 4.8 Kw system here

I'll drag one of the transformers out and get it wired up in the shack
, 250 VA should manage most of the shack equipment.
All noted Neil thanks, and Gordon the zeners would need to be big , on
a bright summer day I've seen 4.3KW generated
Thanks
On Sun, 2018-11-18 at 12:10 +0000, Andy G4JNT wrote:

> I've just spoken to my sister who is very proud of her "green
> credentials" and has a solar PV system. In an urban area (near
> Stourbridge) her system is generating 2.4kW and the mains voltage
> (once I'd explained which of the myriad values presented on the
> monitor panel I wanted) was showing 250.8V
>
> So even with a stiff modernish underground wiring system, it still
> rises appreciably. Within spec, but higher than preferred.
> Forgot to ask how many others in the street also have solar.
>
> Andy
> www.g4jnt.com
>
> Virus-free. www.avg.com
>
> On Sun, 18 Nov 2018 at 11:41, Andy Talbot <andy.g4jnt@gmail.com>
> wrote:
>
> If you have a spare mains transformer with 15 to 20V secondary,
> connect the secondary in anti-series with the mains to drop the
> voltage by this amount
>
> Andy
> www.g4jnt.com
>
> Virus-free. www.avg.com
>
> On Sun, 18 Nov 2018 at 11:37, Richard <richard@g8jvm.com> wrote:
> Hi
> back on QRP again on 23 cms
> the 2C39s , new pair just flashed over again.
> I know what the problem is , my mains voltage is up at 255 ~260 V,
> so the 1300 V on the anodes is way up.
> Its a nice bright sunny day and the SolarPV is pushing the mains
> voltage up.
> When I put the new valves in last night it was dark and the amp was
> nice and stable, so was the mains voltage.
>
> A warning to others if they have ,or their close neighbours have
> SolarPV and high voltage power supplies TWTs etc.
>
> That PA with a pair of 2C39s had been in use for years without
> problems, until the solar panels were fitted.
> Not a problem with switch mode supplies as they are usually able to
> withstand high mains voltages.
> If anyone says the mains voltage doesn't go that high, just look at
> the
> regulations, the inverters are allowed to go up 270V..
> Sorta mega miffed at the moment and thats being polite
> The mains transformer on the linear doesn't have taps to get the
> voltage down.

--

Best wishes /73
Richard Bown

Email : richard@g8jvm.com

HTTP : http://www.g8jvm.com

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