[600MRG] WG2XIQ U3 Experiment - loading a 102" pipe on 630m

[Brian, WA1ZMS]

Keep in mind that as a transmitting antenna, a small loop is very hard to tune. A big 300ft loop of wire around the yard is much better. But if the idea is to try a 5ft sq loop for TX, the ERP will be all but nil.

In RX mode the gain is also nil, BUT you can use the very deep null of the antenna to improve your RX SNR greatly. My 18" loop is on par with my 160m dipole feed as a T-antenna just for the fact that I can null the noise.

Think back to the days when the Isotron HF antenna was the latest thing. Was the SWR Low? Yup. (but so is my dummy load). Could it be tuned around the band on 80m? Yup. But the Q was so high that BW was a limitation.  I don't ever recall seeing a measured gain spec on them, but it had to be many, many dB below a simple dipole.  That said.....they did offer an option for hams who couldn't put up a classic dipole. So something was better than nothing. I've never had a QSO on my dummy load. :- )



-Brian, WA1ZMS/4
(sent from my over-priced iPad3)

> On Jan 22, 2014, at 7:01 PM, WE0H-Mike <we0h at yahoo.com> wrote:
> 
> I had a very nice 200' #8 THHN TX loop for 600 meters until a tiny tornado came swinging thru one day and destroyed it :-( I retrieved a lot of the wire but it was in many pieces. The loop tuner is still hanging on the tree though :-(
> 
> One or two of the NE guys ran a TX loop the last I remember. They work excellent on 1750 meters and no doubt will work on 600 meters. I don't recall how mine worked as it was in the very early days of us guys operating on the band.
> 
> Mike-WE0H
> /16
> 
> 
> 
> Dick B wrote:
>> Greetings everyone
>> 
>> Has anyone here messed-with a tuned loop on 600-meters. At the QRP levels
>> provided by the Ultimate-3, high arc-over voltages  would, I suspect, not
>> present significant problems. Correct me if I am wrong so I do not
>> re-invent a failed project !
>> 
>> 73 - Dick/w7wkr XSH/26
> 
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