I have a length of Lmr-400 for sale if anyone is interested
Sent from my iPhone
> On Sep 4, 2019, at 7:31 PM, Gedas <w8bya@mchsi.com> wrote:
>
> David, I have no personal experience with the M&P coax so I am just going by
> what I saw on their web page. Some observations:
>
> It looks like it has very good initial shielding effectiveness but I wonder
> how the SE degrades after a fair number of flexes and regular use. It seems
> it is not rated for more then 15 bends at a 2" bend radius (that would be a
> show stopper for me).
>
> The power capacity at 10m is only ~425W (on a hot day). The loss for a 100'
> length at 10m is better by 1.2 dB compared to RG-400 but given it's low power
> rating you would never use this coax for a long run out to the antenna
> anyway. Also I am not sure if you must use a special (proprietary) connector
> with this cable but if you do they might be more costly and more complex to
> install then those made for RG-400.
>
> One of the nice things about RG-400 is it is rugged, flexible, and uses a
> Teflon dielectric. It can be bent tightly, even at very high power levels and
> elevated temperatures without degradation.
>
> Maybe someone who has used this cable can chime in but I think I would stick
> with the RG-400 for the majority of ham applications.
>
> Gedas, W8BYA
>
> Gallery at http://w8bya.com
> Light travels faster than sound....
> This is why some people appear bright until you hear them speak.
>
>> On 9/4/2019 6:03 PM, David Aslin G3WGN wrote:
>> Messi and Paolini have a double screened 5mm coax - Hyperflex 5. Copper
>> foil first screen then 88% coverage second screen. Inner is 19 strand bare
>> copper; attenuation at 28MHz around half that of RG58.
>> This would seem to be a very well screened cable for short jumpers; I'm
>> wondering why I would choose RG400 at several times the price of the M & P
>> product?
>> Hivemind thoughts?
>>
>> I recall K9YC reminding us that the resistance of the screen is a factor in
>> bonding our equipment via the coax, so this may be moot - larger cables have
>> lower DC resistance and therefore a 10mm/0.4" cable may be a better choice.
>> Again, thoughts appreciated.
>>
>> All relevant to my SO2R/MS/M2 station build
>> 73, David G3WGN M6O
>>
>>
>> -----Original Message-----
>> From: Gedas [mailto:w8bya@mchsi.com]
>> Sent: 04 September 2019 20:32
>> To: towertalk@contesting.com
>> Subject: Re: [TowerTalk] Preferred type of coax to be used for jumpers in a
>> multi-operator room ?
>>
>> It will depend on who makes the cables you are comparing. If both are
>> M17 rated then both should be double shielded and use silver coated copper
>> conductors which is good but some manufactures may use 95% braid coverage
>> while some may use less. Some may use 95% for both shields others may use
>> 95% for the outer and less for the inner. Also the angle of the weave also
>> affects the shielding effectiveness. This SE will also vary with frequency.
>> But in general, esp for HF use, you will find both to have similar shielding
>> performance as long as you stick to a known trusted & respected name brand.
>> Also keep in mind the dielectrics are totally different between the two.
>>
>> Gedas, W8BYA
>>
>> Gallery at http://w8bya.com
>> Light travels faster than sound....
>> This is why some people appear bright until you hear them speak.
>>
>>> On 9/4/2019 2:54 PM, Stig Lindblom wrote:
>>> Gents;
>>>
>>> We are rebuilding a contest station operating room (HS0ZAR@HS0ZGD) and
>>> need to do a lot of new jumpers.
>>>
>>> Ref. advise below from K9YC (tnx) we will use RG400 (or similar) for
>>> short jumpers.
>>>
>>> Considering to use RG214 (double shield) for longer jumpers, and for
>>> coax-stubs as well.
>>>
>>> How is the measured, or experienced, shielding of RG214 compared to
>>> the
>>> RG400 ?
>>>
>>> 73 de Stig
>>>
>>> LA7JO _ HS0ZGD
>>>
>>> On 8/6/2019 6:50 AM, Gedas wrote:
>>>
>>> And. the conductors are Silver plated, copper clad steel.
>>>
>>> ------------------
>>>
>>> Clarification for other readers. The center of RG142 is silver coated
>>> copper coated steel, the center of RG400 is stranded silver-coated
>>> copper. Both have double silver-coated copper braid shields.
>>>
>>> Loss is about the same as RG58 -- in other words, fairly high. The
>>> principal virtue of these cables is their superior SHIELDING, which is
>>> a LOT better than most braided coax. You only want to use this stuff
>>> for short jumpers.
>>>
>>> I've been happy with at least two purchases of Harbour Industries
>>> RG400 that I've found on ebay from a US vendor. Harbour Industries is
>>> based in VT, and has a presence across the border in QC. NA6O was
>>> happy with the RG400 he bought from China.
>>>
>>> 73, Jim K9YC
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
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