I have been involved with beta testing for the Hi-Z 4 and Hi-Z 8 arrays.
The testing involved two different sites with Hi-Z 4, Hi-Z 8 (160 version),
and Hi-Z 8 (80) arrays. The majority of my testing involved performance
evaluation with very low signal levels in a very low noise environment.
Testing involved the standard antenna amps as well as the new Plus6 amps
(the Plus6 performance is quite good). Coincidentally I have found the Hi-Z
systems to be robust with regard to avoiding damage due to reasonably high
RF exposure (from TX antennas) as well as not passing through excessive RF
to the rig receive port when under those conditions.
73. . .Dave
W0FLS
----- Original Message -----
From: "Hardy Landskov" <n7rt@cox.net>
To: "Ignacy Misztal" <no9e@arrl.net>; <topband@contesting.com>
Sent: Wednesday, January 04, 2012 8:14 PM
Subject: Re: Topband: 4 sq receive and high power
> Ignacy,
> I have a K7TJR 4 square. In fact I was one of the beta testers way back
> and
> I have measured +15 dBm using an HP 435A power meter on the 4 square when
> transmitting 1500 watts on my Delta Loop which is 160 feet away. The
> receive
> patterns are very distorted according to EZNEC when I put all the towers
> and
> antennas in the file BUT it still works great and I have not had any rx
> amp
> failures. I was surprised but the Hi-Z amps are very bullet proof.
> 73 & HNY Hardy N7RT
>
>
> ----- Original Message -----
> From: "Ignacy Misztal" <no9e@arrl.net>
> To: <topband@contesting.com>
> Sent: Wednesday, January 04, 2012 6:47 PM
> Subject: Topband: 4 sq receive and high power
>
>
>>I was planning to buy a 4 sq receive system for the upcoming CQ160
>>contest.
>> One question is about handling of high power when the 4sq cannot be put
>> far
>> away from the tx antenna. HI-Z claims that their system is immune to high
>> power. DX Engineering claims the opposite and requires a sequencer. The
>> sequencer adds complexity and cost.
>>
>> Did anyone experience a damaged amp in those systems? Would clamping the
>> input of a vertical with 2 back to back diodes be acceptable?
>>
>> On a different note, the Hi-Z site states new legal problems and no
>> sales.
>> There 4 sq was about $770 with new amps. However, DX Enginnering has an
>> "electrical only" option to HI-Z for $799 that appears equivalent to
>> Hi-Z.
>> However it is sold out. So neither is available. Not sure there is
>> another
>> viable option.
>>
>> Ignacy, NO9E
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
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