Sick as a parrot!

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daveB
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Joined: 07 Oct 2014 16:49

Sick as a parrot!

Post by daveB » 16 Sep 2018 14:33

I am feeling as sick as a parrot! - as the saying goes. We went over to my daughter's new house on the Isle of Grain to baby-sit and I took my Tecsun PL380. Incidentally the tuning and volume controls are very dodgy now - almost scheduled for the skip. So I checked the MW band in the late afternoon, then around the hour at 2000, 2100 and 220 BST whilst sitting in the garden.

Why am I as sick as a parrot?
1) In the afternoon on 1008 KHz GrootNieuwesRadio (HOL) was received completely interference free! At my QTH, in the garden, when there is no obvious interference - it is weak and noisy.
2) in the late evening on 1521 kHZ I got clear reception of the shut down of the Russian service on CRI followed by their close down music, plus Chinese on 1377 and 1098 kHz which faded up to quite a good strength. I wasn't able to confirm HLAZ on 1566 as Hindstani Radio (HOL) was dominant. Of course with a manually tuned single channel radio I could only check one station on the hour to get an id.

So there must be a huge amount of background noise, not eliminated by the loop, at my QTH - even without the obvious interference. However the loop/SDR combination without the obvious interference is better than the Tecsun PL380 for signals - that's using the Tecsun PL380 out in the garden by the loop.

I'm fantasising setting up an SDRPlay RSP1A at their house and remotely accessing from here, but a)I don't they would appreciate being asked to adjust the loop direction at 11 pm :lol: b) Murphy's Law says that a massive sorce of interference will appear shortly after commissioning :(
SDRPlay, AirSpyMini, RTL dongles, SB920s, Yamaha TX930. 5 ele compact yagi on rotator at 18ft agl. FM5 facing east, FM5 facing south, FM3 facing NE, OIRT dipole, 3-ele Moxon vertical facing east.

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KnobTwiddler
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Location: North London

Re: Sick as a parrot!

Post by KnobTwiddler » 16 Sep 2018 15:08

I expect everybody on the forum is fed-up with me moaning about the pirates and congestion on Band II, but I also have a massive amount of noise on the MW and SW bands.

I couldn't do much about the high electrical noise floor caused by the Railway and PLA devices, but I found that a lot of noise was also down to common mode interference being picked up on the feeder cable. I watched this video and added some common mode chokes and that has lowered the noise by about 25% - It's still not perfect, but as they say every little bit helps >> https://www.youtube.com/watch?v=0JnBX_7usl0
AirSpy HF+ SDR + Full-wave Loop for FM + Home-brew Mini Whip for LW/MW/HF or 9:1 Balun + Whip Aerial
Yamaha T-D500 Tuner For DAB - Alinco DX-R8 Comms Rx - Tecsun PL-880 & ICR-110
Yaesu FT-897D - Icom IC-2200H - Anytone AT-588 for 70Mhz

tvdxrools
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Joined: 01 Oct 2015 07:11

Re: Sick as a parrot!

Post by tvdxrools » 16 Sep 2018 15:21

ferrite ferrite and more ferrite and when you think you have enough add more and also a good grounding helps and not just a 4 foot copper pipe , get as much copper in the ground as you can and even add radials ,it might sound a bit much but every bit helps , David
perseus sdr
400m beverage 320 deg
400m beverage 240 deg

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John Faulkner, Skegness
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Re: Sick as a parrot!

Post by John Faulkner, Skegness » 16 Sep 2018 16:10

Ferrites do sometimes work. Just 'sometimes'. They did work VERY well for me some years ago, but have been futile at this address.

What you could try Dave (and please forgive me if I've already suggested this.) is a flag antenna. Loops are bi-directional, as you know. The flag is uni-directional. This could work *if* your interference is off the back of your wanted direction.

tvdxrools
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Joined: 01 Oct 2015 07:11

Re: Sick as a parrot!

Post by tvdxrools » 16 Sep 2018 16:20

was just about to suggest that john or a ewe , paul crankshaw uses one on mw 160m infact up to 10m , David
ps i think i may be ocd when it comes to ferrite , in the shack they go on everything lol
perseus sdr
400m beverage 320 deg
400m beverage 240 deg

satnipper
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Joined: 03 Oct 2014 12:58
Location: Western Europe

Re: Sick as a parrot!

Post by satnipper » 16 Sep 2018 18:56

All ferrite is not born equal...Cheap ferrite is useless - don't skimp on it.

This page is the bees knees - http://www.ifwtech.co.uk/g3sek/in-prac/

Fair-Rite 31 clamp-on core, Part No 0431177081 for mains cables and Fair-Rite part number 2643167851 for other thinner leads. Davey H is right - ferrites on everything. If you are not spending a decent three figure sum on these ferrites you are not taking it seriously. Seriously.

These ones do work - fixing crap computer power supplies. However they are not all powerful - your neighbour installs solar panels, PLA, plasma tv and cheap Chinese switch mode rubbish you will struggle....

May the ferrite be with you

Stuart

satnipper
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Re: Sick as a parrot!

Post by satnipper » 16 Sep 2018 19:03

And a Flag antenna is a superb beast. Uni-directional for MF and works very well on 48m and even up to 10m as Davey H says. I always give him credit for introducing the Flag to me. Pay attention to the balun tho I'm not convinced the exact number of turns and turn ratio is that critical. The BN-73-202 with very thin copper wire (26 swg is good) is always recommended for home-brewing tho there's an ebay seller who sells baluns for EWE/Flag/Bevvie and fixed and variable resistors which work fb.

May the flag be with you

Stuart

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John Faulkner, Skegness
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Re: Sick as a parrot!

Post by John Faulkner, Skegness » 16 Sep 2018 19:37

I have ferrited around with these things for years, but there is good advice in choosing a quality ferrite - and with the right 'values', though I never understood that bit. I have never known a clip-on to work yet, but I'm sure some must do. I have had cheap and high quality Fair-Rite too.

pnoelw
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Joined: 24 Apr 2016 16:54
Location: Clacton-on-Sea

Re: Sick as a parrot!

Post by pnoelw » 18 Sep 2018 18:38

Thanks for the Fair-Rite pointers - I have ordered 10 of the flat cable core to get started on the USB cables.

Stuart - is it best to use these at the computer or peripheral end of the cable, or should they be used at both ends? Does their weight reuire some sort of support to prevent the cable from easing out of the port?

KPC850
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Joined: 20 Aug 2016 15:49

Re: Sick as a parrot!

Post by KPC850 » 18 Sep 2018 19:11

daveB wrote:
16 Sep 2018 14:33
Why am I as sick as a parrot?
1) In the afternoon on 1008 KHz GrootNieuwesRadio (HOL) was received completely interference free! At my QTH, in the garden, when there is no obvious interference - it is weak and noisy.
Probably more to do with being right beside seawater than less noise at the location. With MW, there can be a significant boost in signal strength right on the coast compared with just a few miles inland, even with long distance MW stations from inland.

satnipper
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Location: Western Europe

Re: Sick as a parrot!

Post by satnipper » 19 Sep 2018 01:05

I use at both ends but if I only had one it would be where the lead enters the mains or device. yes - they are heavy and so you need to be careful the lead does not come out.

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