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Gun G/SP-013, 50mW Activation, Very Short Report


#1

Firstly, let me apologise for not getting back to everyone who called in yesterday. The QRM on Gun proved to be utterly diabolical using a hand held and collinear …even using the very expensive Yaesu VX-8GR. Clearly, hand held filters are no match for the likes of 817/857 rigs. I managed to work about 17 stations on 50mW before upping the power to a couple of Watts, then finally chucking the towel in after about five more contacts.

Rob G0HRT, I heard your call and tried my best to get you on 50mW, but you just moved off frequency as I responded (I’d just taken a phone call). I did my best to find you, but alas, no luck.

This was an extremely interesting experiment, the furthest contact, I think, was down in Worcestershire although much further contacts should be easily achievable.

Anyway, I’ll sling the Yaesu handheld in the bag and take the collinear along for tomorrows activation of G/SP-011 Freeholds Top and maybe try 50mW again for half an hour …subject to QRM conditions. For anyone who fancies a bit of a challenge, I’ll post something on the spots to this effect.

73
Mike 2E0YYY


#2

In reply to 2E0YYY:

even using the very expensive Yaesu VX-8GR

The very expensive VX-8 is well known for it’s rather poor RF performance when using any antenna including the supplied “pliable mallard”.

Andy
MM0FMF


#3

In reply to MM0FMF:

In reply to 2E0YYY:

even using the very expensive Yaesu VX-8GR

The very expensive VX-8 is well known for it’s rather poor RF
performance when using any antenna including the supplied
"pliable mallard".

Must admit to being slightly dissapointed with its performace, Andy. I swapped over to the Wouxun for the 2 Watt bit of the activation an noticed very little difference on receive. Maybe a bit more attention to the VX-8GRs RF performance and a bit less attention to the “bells and whistles” aspect, should be the order of the day for Yaesu.

73
Mike 2E0YYY


#4

In reply to 2E0YYY:

Hi Mike,

You shouldn’t have any QRM (or more correctly intermodulation )problems on Freeholds Top. I used my VX7-R on that summit with no problems at all.

Hope to work you, but maybe not with 50mW :wink:

Best 73,

Mark G0VOF


#5

In reply to G0VOF:

There are a few reports out about the VX-8 and its easily overloaded RF stages. Even as far as it being unusable on hill tops using its own rubber duck never mind an antenna with gain.

Andy
MM0FMF


#6

In reply to MM0FMF:

Hi Andy,

I should have said that I was using my VX7-R with its standard helical, so it may have suffered a little if I had connected a larger antenna, but from what I could hear anyway on the standard antenna, Freeholds Top is a very long way from being in the same league as G/SP-017 Billinge Hill or GW/NW-070 Great Orme.

I am very guilty, as I am sure many of us are of referring to receiver overload as QRM when I suppose that should only apply to man-made interference that is actually real. i.e., present regardless of the receiver in use rather than only existing due to a failure of the receiver circuitry to handle large signals near to either the frequency in use, or any of the receiver’s intermediate frequencies.

Being fore-warned is being fore-armed & I am sure there are many more summits that will swamp the receivers of the modern generation of wide band all singing all dancing handhelds than the two summits I have mentioned.

As suggested elsewhere on the reflector, it is well worth checking the summit information for a particular summit before setting off for an activation armed with only a handheld. You may be in for a shock when you find you can’t hear anybody calling you & your s-meter is reading S9+60db on all channels, especially if you have put a lot of time & effort into getting there.

Older radios such as the Yaesu FT290R cope well because they were designed & built to do one thing & one thing only. It was designed to only cover the 2 Metre amateur band with either SSB CW or FM. It did not have “extended receive” or “airband receive” or any of the other bonus features that virtually all modern amateur VHF transceivers have, & its filtering was designed accordingly.

I have to say, that despite hearing from several activators that the Yaesu FT817 could also cope well with Billinge Hill type signals, I had to see for myself, hence another reason for my “activation” very early the other morning. I had done some simple tests with my FT817 at home previously that indicated a sharp drop off in sensitivity once you move away from the 2 Metre band. This would indicate that the filtering has been designed with rejection of strong Having tested it “in the field” on Billinge Hill I have to say I was pretty amazed that a radio that does offer so much coverage, still coped admirably in very strong RF environment.

On a similar note, while I was on Billinge Hill I took a close look at a couple of the commercial masts & I have to say it must be a nightmare for a radio engineer to find the source of any breakthrough their equipment may be suffering. The layout of some of the antennas is “pretty mad” in my opinion, & I think there should be a least another lattice tower up there for some of the antennas to be correctly spaced. Maybe that’s why there does seem to be such a large number of antennas crammed in such a small space on the masts already there.

It would be interesting to know if the “QRM” on GW/NW-070 Great Orme, sounds the same as that on G/SP-017 Billinge Hill. I wonder if anyone who has activated, or tried to activate GW/NW-070 Great Orme with a 2 Metre handheld could confirm this?

My video of Billinge Hill “QRM” is here (again!) Sorry :wink:

Best 73,

Mark G0VOF


#7

In reply to G0VOF:

In reply to MM0FMF:

Hi Andy,

I am very guilty, as I am sure many of us are of referring to receiver
overload as QRM when I suppose that should only apply to man-made
interference that is actually real. i.e., present regardless of the
receiver in use rather than only existing due to a failure of the
receiver circuitry to handle large signals near to either the
frequency in use, or any of the receiver’s intermediate frequencies.

Which ever way you slice it, the band was barely workable, Mark. Never heard screeches and howls like it.

Being fore-warned is being fore-armed & I am sure there are many
more summits that will swamp the receivers of the modern generation of
wide band all singing all dancing handhelds than the two summits I
have mentioned.

Yeah, never truer words spoken, Mark. I’ll certainly have to change the plans for my proposed G/LD-001 activation next month. May even have to get on my hands and knees and ask G1STQ for the loan of his 817 :wink:

Catch you tomorrow…

All the best
Mike 2E0YYY


#8

In reply to 2E0YYY:
If you are aware of the damage done to his own FT-857 when butter fingers managed to drop it on a sharp and pointy rock…do you think I’d be stupid enough to loan him my still-as-new FT-817 :slight_smile:

Think I’d prefer it if Mickey had asked to borrow my wife! (Free delivery during June).


#9

In reply to G1STQ:

In reply to 2E0YYY:
If you are aware of the damage done to his own FT-857 when butter
fingers managed to drop it on a sharp and pointy rock…do you think
I’d be stupid enough to loan him my still-as-new FT-817 :slight_smile:

All now beautifully repaired at the radio club last Thursday, with parts costing a mere £12.50, delivered in less than 24 hours from Yaesu :slight_smile:

Think I’d prefer it if Mickey had asked to borrow my wife! (Free
delivery during June).

LOL… Lets hope she don’t read the Reflector :wink:

Mike
2E0YYY


#10

In reply to 2E0YYY:Hi Mike I was on SP013 on Saturday and I was using an Icom IC T90.No QRM problems at all ATB Geoff G6MZX