Friday, October 16, 2009

On Grike with the MFD

It has been a glorious day here in the English Lakes - clear blue sky with the occasional cloud, the temperature around a fresh 12 degrees C, ideal for walking. So I took the opportunity to try out the new Multi Function Dipole from SOTA Beams, which arrived yesterday. (My wife and I have an agreement: I will say nothing about all the shoes she buys if she will be equally circumspect about my antennas.)

I thought I would take the opportunity to do a Wainwrights On The Air (WOTA) activation at the same time. I chose Grike, a minor fell in the western Lake District, as it is a fairly short drive from home and an easy walk to the summit.

It was quite breezy on the top so I was glad that someone had built a stone shelter, though the wind was from the wrong direction and the best place was outside of it. The MFD was very quickly put together and connected to the VX-8E, and I tuned to 145.475, the frequency I had preannounced I would be using on the WOTA activations page.

I was surprised to find what seemed like interference on that frequency at about S3. Turning the dial, the S-meter reading steadily increased and I discovered that there was an enormous signal apparently centred on 145.625, the output of the Isle of Man repeater GB3GD. Wow, I thought, either the MFD is very good or the VX-8E receiver very poor to be de-sensed as much as that by a repeater on an island a few tens of miles away. Subsequently I called through GB3GD and it was not that strong, so the identity of the monster signal remains a mystery.

A call on 145.500 produced a contact with Keith, G0EMM in Workington, who complained that my signal was so strong it would be ruining his S meter if it had a needle. Keith is a WOTA chaser, so that was a good result. However, further calls on the simplex calling frequency and on all of the repeaters I could access from there, which is quite a few of them, only produced one more contact with Clive, GM4FZH, near Whithorn in south-west Scotland. Where has all the 2m activity gone?

My VX-8E APRS channel decoded several APRS packets from stations in Ireland, presumably digipeated from EI2DBP running 25W to an omnidirectional antenna, more than 200 miles distant. I also heard some Irish stations speaking on the calling frequency while I was taking a photograph, but when I put out a call they declined to come back to me.

I wasn't able to try any A/B comparisons between the MFD and the rubber duck supplied by Yaesu - perhaps another day - but the MFD certainly makes a difference. I could access the GB3LD repeater in Lancaster, to the south of the Lakes, using the MFD but not when using the duck. I also appreciated being able to sit on the ground out of the wind while having the antenna up in the clear where it could get the best signal. The MFD weighs next to nothing so even a wimp like me won't find it makes the rucksack too heavy. I think that for WOTA activations this little antenna is a real winner.

7 comments:

Paul said...

Hello Julian, I think the MFD is a lot better than the a rubber duck antenna. I wonder myself about the lack of activity on 2 meter here. They don't like VHF anymore? 73, Paul PC4T

Jspiker said...

Hello Julian,

I assume this is a "J-pole" mounted in a pvc pipe?...a great idea for those spots where they're not many trees in high places!

Can't think of a way to hang my "roll up J-pole" in a place like that.

I like working from "hilltops" also but haven't done much in the last several years since getting into HF.

Although cold...it looks like you enjoyed yourself. This morning it was 33 degrees here...winter is coming quickly.

Have you ever tried "geocaching"? Is it popular over there in England?

It's a great opportunity to work 2 meters while spending a day outdoors. My last count was 122.

N8ZYA QRP

g4ilo said...

Hi John. Actually it's a dipole. I had an idea to make an antenna similar to that but using a Slim Jim (essentially the same as a J Pole) made of 300 ohm ribbon cable but I never got around to it so I thought I would try this ready made one.

The advantage of using a dipole is that it can easily be reconfigured horizontally for use on SSB with an FT-817, which many hill-toppers are keen on.

No, I have never tried "geocaching". I've heard of it, but thought it had more to do with GPS than ham radio.

Palmtopman said...

Hi, I've just ordered an MFD for use with my Yaesu VX-8. I hope that the MFD doesn't bring in too much noise? I have experienced an external antenna on my VX-8 in a residential area to increase the noise and have been told that the VX-8 was being over sensitised with the ext-ant, rather than using the rubber duck that came with it. I don't intend to use the WFD in residential areas, rather when out for the day and occasionally during a RAYNET duty. I hope the WFD works well with my VX-8?
73,
Ozzie
G1OFL

Julian said...

The VX-8 (like many other small handhelds) is rather prone to receiver overload when using an efficient antenna especially on hilltops. I have experienced it with the MFD and also with a 5/8 wave telescopic whip attached using a SMA to BNC adapter, which has similar gain. It's still usable (unless perhaps you are very close to a commercial radio mast) but be prepared to hear some strange things.

I have a Motorola GP300 handheld which has a must stronger receiver in that respect. I believe many Raynet groups use them.

Anonymous said...

Thanks Julian, just ordered one.. 73

vebo said...

hi julian i bought an mfd antenna for indoor house/flat use and it`s great as well as using it on raynet and outdoors. :))