[TowerTalk] For Sale: PolyPhaser IS-3T1 12 Cond in line protector

[Steve Davis -Davis RF Co.]

Hi TT'rs,   The circuit consists of mosfet/zener/resist series-par, thus 
comprehensive in design.  I'm glad to provide a photo of the circuit to 
anybody seriously interested.  Moreover, check out the specs on this one.... 
if it suits your application, fine (I'll send a copy of the PP catalog page 
specs). PPHaser engineers are open to ham call inq's...ask them if their 
spec "Multi-strike industrial use" means that this model could be subject to 
degradation of the circuit due to transients (let alone the spec'd 36,000 
amps IEEE 8/20 waveform based on ANSI C62.1).... another reason not to use 
gas tube components. tel: 775 782 2511
  Also, read Jim Lux's comments, makes several pertinent points.
  I  would not recommend   gas tube types  for the applications that this 
unit is designed for.
   Lastly, the rated bandwidth IS limited (as all are)......  on this one,
> 30 MHz, not bad in my book .
  Lots of folks have issues with PPHaser pricing, but in my case, I receive 
calls for insurance estimates after equipment is destroyed (not to mention 
my friends house a total loss, and his dog dead).  They always THEN buy 
PPHaser.
  73, Steve   K1PEK

----- Original Message ----- 
From: "jimlux" <jimlux at earthlink.net>
To: "Steve Davis -Davis RF Co." <sdavis at davisrf.com>
Cc: <towertalk at contesting.com>
Sent: Saturday, March 14, 2009 11:12 AM
Subject: Re: [TowerTalk] For Sale: PolyPhaser IS-3T1 12 Cond in line 
protector
gas tubes are nice, but if you're protecting something that has a low
damage threshold (like the inputs to most ICs), they're not the right
technology.

Something like a gas tube (to limit the max voltage to 50-100V, or
whatever), followed by a resistor (to limit current) and suitable low
capacitance diode clamps (to limit to the supply voltages) might work
better. Hopefully, that's what you're getting with a more expensive
transient protection device.

Fast data is a real challenge, because the C of the diodes limits the
bandwidth.  Choosing a different driver/receiver chip in the device to
be protected can help (because an onchip clamp is lower C than an
external devie)  ""  (Jim Lux)



> Steve Davis -Davis RF Co. wrote:
>> 12 conductor protection, T1, data line protector, multi strike, 36,000 
>> Amps. RS232/422.  6 twisted pair (or single conductors up to 12 
>> conductors).  Cast alum enclosure and all hardware SS. Surface mount 
>> right angle brackets (4). Specs, picture and drawing: 
>> http://www.polyphaser.com/productdetail.aspx?item=IS-3T1
>>    Excellent condition.  Original price:
>> $ 343.00 .   Selling now:  $ 195.00 plus shipping, insur, tracking. 
>> This is from my personal ham equipment and I will guaranty it works. 
>> Contact me off TT please.
>>   73,  Steve,  K1PEK
>
> Something to be aware of when using such devices (not directed at Steve 
> here, but because I happen to be writing up something on these for another 
> reason, and this reminded me of it)
>
> There's 4 basic schemes used for protection inside this kind of box 
> (oddly, PP doesn't say which in their datasheet, for this particular 
> device).. a gas tube, a back to back zener diode, a MOV, or a series L, 
> shunt C sort of arrangement.
>
> The MOV style wears out. Everytime a transient comes down the line, the 
> MOV dies a little bit. (that's what leads to those plug strip fires)
>
> All of the data protectors have a voltage rating, which can bite you if 
> you're not careful.  Hooking a 24VAC relay control on a 7V telecom 
> protector will probably cook the protector (Yes.. I should have found the 
> datasheet before hooking it up.)  Watch out for RMS vs Peak voltage too, 
> especialy if you're using a device that is usually for DC applications 
> (telecom)
>
> The PP IS series has been replaced by the PP IX series.  I don't know all 
> the differences, but the IX (for some part numbers) is UL listed, so if 
> you're worried about NEC compliance, check first. None of the usual ham 
> coax devices from PP is UL listed, so they can't serve as your "listed 
> antenna discharge unit" for instance.
>
> Jim, W6RMK
>
>