[TowerTalk] Medical offices near possible new club site

Mike Smith VE9AA ve9aa at nbnet.nb.ca
Fri Aug 14 18:37:23 EDT 2015


Jim is of course correct and I made the fatal error of getting interrupted
when I wrote that last email and failed to finish my train of thought when I
came back to sit down and type.

I'm actually employed in Clinical Engineering (AKA BioMedical) so am quite
familiar with medical equipment (that's what we do)

 

In addition to CSA/UL(and equivalent) standards, medical equipment (at least
north of the border) must possess a medical device license, which covers
other things on top of pure safety which Jim has explained.

In addition to that, the GOOD manufacturers (of their own accord)  often
employ additional ferrite filtering, metal cases, conductively covered
plastic cases (inside, usually a paint or film) and whatnot, thus my feeling
that it's probably not really the medical equipment that should be his first
worry !  I operate the CWT's pretty darn well on 20m a mere 50' from a 4
story  bldg. and I never feel like I am fighting the noise all that much..

 

The biggies like GE will even tell you in service manuals how many mV/M2
(meters squared) or at what distance) of RF @ various frequencies that
particular device can stand before its affected negatively.

We've done our own testing in-house and a lot of devices are completely
oblivious to RF until you get up around 1w+ of analog RF right beside it.
Your 100w 100' away will be less than this, so it'll be the annoying things
like your voice over their cheapie computer speakers at the front offcice
that will adversely affect your coexistence.  Or their el-krappo computer
switching power supplies that are S9 from DC through DAYLIGHT. Or that
hastily installed bargain HVAC blower on the roof with an arcing whatever
50'\ from your antenna rendering your HF activities useless.

 

If I had my druthers, I would NEVER, EVER locate a club station in a city.
I can tell you from 30+ years as a mobile ham (and over 37 yrs just a ham)
wheeling around to and fro that cities are getting really loud RF wise.

 

I can't make your decision for you of course, but I wouldn't do it unless
the place was practically free or at the end of the street in a one-horse
town.

 

Too much to risk.

 

Respectfully, 

 

Mike VE9AA/often mobile

 

On Fri,8/14/2015 1:05 PM, Mike Smith VE9AA wrote:

 

 

it's all CSA (read UL to you) approved.

 

 

 

UL and CSA are SAFETY Testing Standards ONLY. The test products to show that
1) they cannot start a fire and 2) they do not provide an opportunity for
electrical shock. In the case of wiring, they also test for noxious fumes
subjected to flames, and will not support flame spread (in response to the
Towering Inferno, which was a very real event in a building). In general, UL
and CSA do not test that a product works, nor do they test for RFI. 

 

I agree with Mikes's suggestion of a serious survey with a mobile rig, and
at multiple times of day. The frame of reference should a QUIET location. Go
to that quiet location, set up and tune the mobile antennas (if they are
tunable) write down the S-meter readings on each band for the relevant
antenna(s). Then compare those readings with what you get driving around the
proposed site. 

In the business world, this is called "due diligence."

 

73, Jim K9YC

 

 

 

73, Jim K9YC

 

 

 

Mike, Coreen & Corey

Keswick Ridge, NB

 



More information about the TowerTalk mailing list