In article <jeio9dFin6fU2@mid.individual.net>, williamwright
<wrightsaerials@f2s.com> wrote:
> On 17/05/2022 23:25, alan_m wrote:
> > And probably work if the aerial is in the loft. A log periodic is an
> > ideal physical package for loft installation.

> No no no! Loft aerials last for ever! What about the poor starving
> children of future aerial men?

Best advised to shift trade into internet network setups. etc. 8-]

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
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Audio Misc http://www.audiomisc.co.uk/index.html

In article <jeiok8FipdmU1@mid.individual.net>, williamwright
<wrightsaerials@f2s.com> wrote:
> On 17/05/2022 23:52, Brian Gregory wrote:

> > Here's one done in a different way:
> > https://www.brian-gregory.me.uk/GDL/spectrumspy-2020_03_10__04_03_33.png
> >
> > It has numerous spurious spikes all over the place.
> >

> It's nice though. You can make the same spectrum look completely
> different by: - Altering the scan bandwidth (makes a massive difference)
> - Altering the scan speed - Altering the start and stop frequencies -
> Altering the dynamic range - Setting 'hold maximum' or 'hold minimum'.

Somewhere I still have a copy of a book that IIRC Tektronix produced to
help people avoid getting weird results or interpretations as a result of
incorrect setup/reading of a swept specan screen. I fear more people bought
specans than ever read the book. 8-]

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
biog http://jcgl.orpheusweb.co.uk/history/ups_and_downs.html
Audio Misc http://www.audiomisc.co.uk/index.html

On 18/05/2022 21:26, Brian Gregory wrote:
> On 18/05/2022 00:00, williamwright wrote:
>> On 17/05/2022 19:32, The Other John wrote:
>>>> The aerial fixings will need to be replaced most likely.
>>> I was afraid you'd say that!  None of the neighbours has got a log
>>> periodic and as we're only 1.5 miles from the TX a bit of wet string
>>> would
>>> probably work:)
>>
>> Even close to the tx the directional properties of a log could be
>> helpful. Also a log has flat response across the band.
>
> Log periodics probably more likely to stay directional when loft
> mounted. My limited experience with loft mounted yagis suggests they
> can be so detuned by damp roof tiles and felt that they end up almost
> omnidirectional.
>
I had the luxury opportunity of comparing the results from my Log P in
the loft, without any roof tiles and then with them. The difference was
about 6 to 8 dB.

It still delivers 60-65 dBuV across the muxes in the loft, so I kept it
there

On 19/05/2022 10:37, Mark Carver wrote:
> On 18/05/2022 21:26, Brian Gregory wrote:
>> On 18/05/2022 00:00, williamwright wrote:
>>> On 17/05/2022 19:32, The Other John wrote:
>>>>> The aerial fixings will need to be replaced most likely.
>>>> I was afraid you'd say that!  None of the neighbours has got a log
>>>> periodic and as we're only 1.5 miles from the TX a bit of wet string
>>>> would
>>>> probably work:)
>>>
>>> Even close to the tx the directional properties of a log could be
>>> helpful. Also a log has flat response across the band.
>>
>> Log periodics probably more likely to stay directional when loft
>> mounted. My limited experience with loft mounted yagis suggests they
>> can be so detuned by damp roof tiles and felt that they end up almost
>> omnidirectional.
>>
> I had the luxury opportunity of comparing the results from my Log P in
> the loft, without any roof tiles and then with them. The difference was
> about 6 to 8 dB.
>
> It still delivers 60-65 dBuV across the muxes in the loft, so I kept it
> there

I had a loft-mounted 18 element Group A yagi for Rowridge (about 30km
SSW) which was fine, but when the COM7/8 change occurred replaced it
with a Log P
(<https://www.amazon.co.uk/dp/B01L62DT7G/ref=pe_3187911_185740111_TE_item>.
No idea why the only rating is one star; it works fine for me). I see no
reason to go back to the yagi when COM7 disappears.

--

Jeff

On 18/05/2022 19:14, Woody wrote:
> If the OP could find one, one of those flying bedsteads of years ago
> would work very well in the loft.

If you mean the stacked full wave bowtie dipole things, they were nicely
directional for VP, but actually rather hopeless for HP.

Bill