Didn't ON4UN give a presentation at Dayton in 2005 that covered his testing
of different 4-square feed systems? I thought his conclusion was that
there was less than a 1dB difference in performance for the quadrature
method, but that it was possible to narrow the main lobe somewhat using an
elaborate LC network to optimize phasing. I'm going from memory (mine not
so good these days - hi) but it might be worth revisiting.
73 & best holiday wishes,
Matt
KM5VI
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Lux, Jim
Sent: Saturday, December 26, 2020 11:50 PM
To: Tim Duffy <k3lr@k3lr.com>; towertalk@contesting.com
Subject: Re: [TowerTalk] 4 square - collins hybrid measurements/component
values
On 12/26/20 8:15 PM, Tim Duffy wrote:
> Hello Jim:
>
> "All the parasitics"???
>
> 73
> Tim K3LR
most practical implementations of the hybrid will have:
1) leakage inductance in the transformer (i.e. coupling factor isn't 1)
2) loss in the inductor (from R in the winding, and loss in the core)
3) C between the windings (basically in parallel with the lumped Cs)
If someone has actually measured one on a VNA, that would be useful.
>
> -----Original Message-----
> From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
> Lux, Jim
> Sent: Saturday, December 26, 2020 9:35 PM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] 4 square - collins hybrid
> measurements/component values
>
> On 12/26/20 5:55 PM, Haring family wrote:
>> No need to duplicate... check ON4UN/5th. He has a model of the
>> Collins coupler included that Roy W7EL made up for EZNEC, I think.
>> Dan AC6LA may have something for it for AutoEZ also.
>>
>> regards,
>>
>> Dave N3AC
>
> I have the 3rd edition which doesn't have the models. But what I'm
> really looking for is measured data on a real box (with all the
parasitics).
>
>
>>
>> On Sat, Dec 26, 2020 at 2:37 PM Lux, Jim <jim@luxfamily.com> wrote:
>>
>>> I'm putting together some models and I was wondering if someone has
>>> actual measured 4 port data for the LC Collins hybrid.
>>>
>>> I've got some sample capacitance and inductance values
>>>
>>> (e.g. for 80m, 436 pF and 2.18 uH)
>>>
>>> I'm assuming that the transformer is "well coupled" so the mutual L
>>> is almost the same as the inductance of the winding.
>>>
>>>
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