[R-390] R 390A Line Filter Trial

[rbethman]

This was posted by Glenn Scott WA4AOS, in Feb 2011.

Folks that are looking at line filter replacement really ought to look 
into this.

The Corcom line filter method is the one used by Tisha and Les Locklear.

Bob - N0DGN



Hi Group,
   I am putting a kit together to replace the old leaky Corcom line 
filters used in the R 390A's  with new Hospital grade Corcom filters.
  The problem is mounting a good quality filter with better specs than 
the original within the existing real estate.
  I came up with a solution using existing holes, a mounting plate with 
standoffs. This is a very tight fit but easy to install.
  The filter will mount behind the PTO and is raised above the wiring 
harness runs in the rear. A rubber hole grommet comes with the kit to 
feed the  line cord to the filter. The filter will additionally include 
3 Varistors and a CL-80 current limiter already installed.
I was not able to find a Corcom or any other  line filter solution that 
would mount where the original filter mounted but this solution is VERY 
WELL DONE and commiserate with the excellent quality within the 390A 
Receiver.
All kits will be pre assembled, tested and burned in for at least 1 hour 
before shipping.

My prototype filter kits are installed in three R 390A receivers 
presently and the installations were perfect as well as professional 
looking.
  I am looking for 5 volunteers who have R 390A receivers to take a kit 
at MY COST, install them and give me feedback.
Already, I know the kit fits into Motorola, Amelco and EAC R 390A's. I 
would like to hear from folks who have other built R 390A's  for the 
trial.   I prefer engineers, technicians or competent long term users of 
R 390A's for the evaluation trial period. No skills beyond operating a 
screwdriver are required but I am looking for professional feedback.


Of course, the usual warnings about working with any line voltages 
apply.You know, unplug the receiver first, capacitors hold charges, wear 
goggles, gloves, hazmat suites, rubber souled shoes, have 911 people 
online the entire time you work, seriously they love R 390A's too,  and 
all of the usual safety stuff we all practice daily.. Oh, keep one hand 
in your back pocket and a carrot in your left ear too. So, if you 
electrocute yourself to death during installation, don't sue me because 
you weren't' warned. Actually, I would prefer not hearing from you if 
you kill yourself putting this kit in... Just saying.. .



  Later, I will offer these kits to users of this reflector ONLY, at a 
discount for a short period of time before I list the kits on eBay and 
my website.
  I would like the filters kits installed and reports back within a 
month. Please don't request a trial filter if you are NOT SERIOUS about 
quickly installing it and reporting your observations to me and the 
users of this reflector. if there are any unforeseen issues, let's find 
out now..


Installation is simple and should not take more than an hour; 
instructions will be included. You simply remove the bottom cover and 
the old Corcom filter. Mount the hardware to the chassis and install the 
filter, No soldering will be required. The kit will also include a new 
line cord and plug with the aforementioned mounting parts.
  So far, I see no reason why this kit would NOT fit into any iteration 
of the R 390A receiver but there are some minor variations in machining.
    If all goes well, I will offer these to reflector users around the 
first of May. I am having the small chassis plates CNC machined this 
week and should have them next week. I will offer a full refund 
including shipping to the participants of the trial evaluation if not 
pleased with my kit or certainly if it will not fit
some variation of machining within the R 390A.
I plan to post some pics in the next week or two for others to view. 
Additionally, I will post some pics of line hash in and out of the filter.



The evaluation will help me understand any installation issues before 
listing these kits are offered to the general boat anchor community on 
eBay and elsewhere.

Please don't beat me up about changing the looks, or the filter isn't 
necessary, or it's not original,.or why didn't I choose a so and so 
filter. If you have a better mouse trap, build it.
I gotta tell you, it was very time consuming to fit this or any other 
filter in the prototype stage. My first 5 ideas and attempts did not 
work out for one reason or another.

>From my perspective, the kit is 100% reversible, prevents people from getting shocked due to differences in potential between the 390A chassis and ground.
I also strove for this to be a professional solution and not be a Micky 
Mouse, kludge attempt at fix something; I see my share of sorry mods 
almost every week. I treat these receivers with great respect and am 
trying to help with a known problem.


Thanks  in advance for reading this post and your assistance to help 
with this project. If you think you might want a filter kit in May, 
please hold off letting me know until the trial is over. As with the 
Fowler manual copies I sold to readers of this reflector last summer, 
about 120 something copies all over the planet, I will make good on my 
offer to list these kits here at a discount for a short period of time.


If you are interested in a trial kit at my cost, will install it 
quickly, report your observations and are technically competent to 
electrically and mechanically critique this kit please contact me at my 
email address listed below, Additionally, first consideration will go to 
owners of 390A variations other than Motorola, Amelco and EAC
built 390A Receivers. Tell me which 390A you have and a little about 
your capabilities.

Glenn Scott WA4AOS
DSM Labs

  My  email address: (((>>>>>>>>>>   glenn @ dsmlabs dot com 
<<<<<<<<<<<<)))















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