Scott's Radio Room for 2023

KC1UA

Scan New England Janitor/Maintenance
Database Admin
Joined
Oct 27, 2002
Messages
2,088
Location
Marstons Mills, Cape Cod, Massachusetts
Decided to try a Behringer RX-1602 for audio distribution again and this time made it work properly. Not sure where my brain was the first time or something was amiss (amok, awry) with the original. Had Colin at Alberta Radio Supply make me a 3U rack plate for my IC-R8600 which uses the same platform as the prior 4U plate. Here are the results after this morning's install.

Middle Rack.jpg
 

PRMII

Member
Premium Subscriber
Joined
Feb 28, 2018
Messages
22
Location
Central Texas
I'd like to compliment you, and say Nice, but I just can't bring myself to do that....
What I can say is, OUTSTANDING!!!!! Very well engineered and setup. I see these, and want to expand again, but I'm getting older, and have reduced my station size. Now, a couple of scanners, HT's, a small and full size HF rig, and a couple of 2m rigs. Push-up pole with just enough antennas, and an end fed half-wave for HF.
But, it's not out of the realm of possibility to jump my ship onto that of others here, and have a really nice shack setup again. When the time comes, I won't be around to hear the kids fuss about "Why did Dad have all this crap?" anyway!
Those who can, keep building nice shacks. Those who can't, if what you have works, that's all that's needed. Now to the shop to start laying out some plywood....
 

KC8ONR

Member
Premium Subscriber
Joined
Nov 13, 2021
Messages
67
Location
bridgeport
First off ........

Very nice Scott. Between you and Rich , you both have inspired me to spend some money. I have an order in for the same rack that you have ( in black ) I am not a very patient fellow and the wait is killing me ( going on 7 weeks ). I would go into detail about the setup, but I'll save it for a surprise :)

Again very nice Scott!
Dan
 

N1SQB

Member
Premium Subscriber
Joined
Jan 25, 2003
Messages
2,761
Location
Somewhere On Earth
Decided to try a Behringer RX-1602 for audio distribution again and this time made it work properly. Not sure where my brain was the first time or something was amiss (amok, awry) with the original. Had Colin at Alberta Radio Supply make me a 3U rack plate for my IC-R8600 which uses the same platform as the prior 4U plate. Here are the results after this morning's install.

View attachment 143854
Scott, very very nice. I have the RX-1602 as well. Seems to have a hum I cannot find but it works. My question is what are you using now for speakers?
Second, I have noticed that our state trunking system as it comes through my 2 SDS200s, sounds very bass filled. All other scanners are lacking the low end. Have you had similar experiences with multiple radios through the 1602?

Manny
 

KC1UA

Scan New England Janitor/Maintenance
Database Admin
Joined
Oct 27, 2002
Messages
2,088
Location
Marstons Mills, Cape Cod, Massachusetts
Scott, very very nice. I have the RX-1602 as well. Seems to have a hum I cannot find but it works. My question is what are you using now for speakers?
Second, I have noticed that our state trunking system as it comes through my 2 SDS200s, sounds very bass filled. All other scanners are lacking the low end. Have you had similar experiences with multiple radios through the 1602?

Manny

This is my second time around with the RX-1602. I removed this one as well and went back to the individual speakers. As you state, my SDS200 sounded terrible through it and I never could find the ground loop. I spent a significant amount of time trying. So for now I have a blank plate above the IC-R8600. Anyone have any other good suggestions for 1U devices?

I'll probably put my 1602 up for sale at some point but I'm done with trying.
 

N9JIG

Sheriff
Moderator
Joined
Dec 14, 2001
Messages
5,702
Location
Far NW Valley
This is my second time around with the RX-1602. I removed this one as well and went back to the individual speakers. As you state, my SDS200 sounded terrible through it and I never could find the ground loop. I spent a significant amount of time trying. So for now I have a blank plate above the IC-R8600. Anyone have any other good suggestions for 1U devices?

I'll probably put my 1602 up for sale at some point but I'm done with trying.
That's odd, I never had any audio issues with my SDS200 (or other scanners) in either of my Behringer mixers, including the 1602. I just used straight-thru mono cables, albeit high-quality ones.

As for filling the space they make a wide variety of 1u power strips with outlets on either side or on both.

I have seen amplified speakers in a 1u panel as well, they could replace the computer speakers for one of your boxes.
 

Mike_G_D

Member
Joined
Dec 19, 2002
Messages
1,242
Location
Vista, CA
Every now and then the issue with the BTL external speaker output of some of Uniden's newer models comes up.

It started with the 536 having only a single external BTL audio external speaker output and no "record" line level output like the earlier base/mobile Uniden receivers had. So people were forced to use the one external speaker output to get their audio into external devices. If the amp were standard single ended relative to ground design this would have been easy but due to the BTL design this caused issues since with a normal two conductor cable you are now shorting one of the tied amplifiers straight to ground (that is bad!) and you get at best some nasty noise and/or distortion and at worst you might just fry one side of the BTL amp (though most modern versions have some protection against this). Presumably this design was carried over to the SDS 200. Back when the 536 came out, as a mental exercise I started working on ways to get around it when patching the external speaker output to line or mic level audio input devices expecting single ended hot relative to ground audio.

By the way - as I recall the response from Uniden for eliminating that old handy "record out" line level output was that the 536 had the ability to send the audio through WiFi now and was able to record it digitally on to memory cards. If you wanted external audio patched to something else besides a speaker then you were supposed to use the WiFi or maybe USB digital audio (sorry I can't recall if it had USB also - think it may have).

Anyway, here's a handy Wikipedia link to get started on understanding BTL amps:


As to what I came up with - see attached.

The "Basic" "solution" is really simple but may not work in all cases - but really easy to try since in the simplest form you just clip the ground/shield connection at the radio end and connect that clipped shield to the radio chassis case (like with a screw, etc.). Again results may vary but it is easy to try.

A slight improvement to this is the added resistive divider and some simple capacitive noise reduction - this is also in the "Basic" zipped file.

If either of these works well for you that may be sufficient. Other simple options that many have had good luck with is the use of commonly available ground loop isolation transformer patch cables. These are basically cables that have an audio isolation transformer in-line and can be found for fairly cheap costs. They sometimes work just fine but results can vary with the type of transformer used and some may or may not have additional level attenuation properties (either thru the transformer ratio or thru additional resistive attenuation or some form of both). These are primarily designed to reduce ground sourced noise caused by ground loops in the audio circuit in mic and line level circuits and not really intended to patch a high level speaker output to a line level input but they can and do sometimes work well enough for that - many have had good success with them as I have read on these forums.

Anyway - after I came up with the basic options I really dived down the rabbit hole and worked on a full circuit that would handle the conversion to line level audio from either type of high level speaker output - single ended or BTL with use of one jumper. See the other attached zipped file.

All varieties are passive and require no external power but they basically take the high level audio from a speaker output and convert it to a line level range using simple resistive dividers and add in noise reduction and provide a "place to go" for the opposite side of the BTL output. They also provide a simple switch for dealing with other sources of ground "noise" if needed by allowing one to fully isolate or ac couple the ground if standard DC coupling is not working well.

They also all have the ability to connect an external speaker at the same time as providing a line level to the external device but, of course, the setting of the volume in the radio will have some effect on the line output (less of a problem in the variable version but still an issue).

Fixed and variable versions (fixed provides one set attenuation so your sole control is the volume adjustment on the radio while the variable version provides some level of external adjustment after you set the volume on the radio to your liking) are available with variable versions most suitable if you need to connect an external speaker as well as your external device so that you can control them separately.

If not using an external speaker (say only going to a mixer as in this case) you can eliminate that part of the circuit.

There are both a transformer version and a direct coupled version of both the fixed and variable varieties (so four total versions).

These were "head exercises" for me and I never got around to building and testing them so feel free to test and modify of course should you decide to build any of them. For a straight shot to a mixer probably simplest to build the fixed level attenuation direct coupled version and leave out the external speaker jack unless you happen to have a 1:1 audio transformer handy in which case you could go for the transformer version.

Readme notes are also in the second zip file if anyone wants to study and/or play with those.

-Mike
 

Attachments

  • 536_extspkrbasic.zip
    52.9 KB · Views: 39
  • scanner_speaker_to_pc_input.zip
    163.7 KB · Views: 26

Rt169Radio

Member
Premium Subscriber
Joined
Aug 24, 2011
Messages
2,972
Location
CT
And here I was thinking I had a good amount of radios, lol. Outstanding setup! (y)
 
Joined
Jul 7, 2009
Messages
7
Location
Columbus, GA
So much to process but well done! Quick question, which has probably already been answered but I wasn't able to find the answer. How tall is your tower? Very nice setup! Newbie here just dreaming!
 

KC1UA

Scan New England Janitor/Maintenance
Database Admin
Joined
Oct 27, 2002
Messages
2,088
Location
Marstons Mills, Cape Cod, Massachusetts
So much to process but well done! Quick question, which has probably already been answered but I wasn't able to find the answer. How tall is your tower? Very nice setup! Newbie here just dreaming!

Thanks to everyone for the continued kind remarks.

To answer your question, to the top of the tower is about 45 feet.
 
Joined
Jul 7, 2009
Messages
7
Location
Columbus, GA
Thanks to everyone for the continued kind remarks.

To answer your question, to the top of the tower is about 45 feet.
I have 7 sections of Rohn 25 but since I’m in a neighborhood I’m thinking about only going up roughly 30 feet. Still getting my feet wet with all of this!
 

K1MLG

Member
Premium Subscriber
Joined
Jul 3, 2013
Messages
13
Location
Ashford, CT
Great set up! Which wood did you choose for the Audio Rax rack? It is very attractive.
Michael
K1MLG
 

AF1UD

Member
Premium Subscriber
Joined
Feb 28, 2022
Messages
298
If you had to do it over again would you get the same piece of equipment from Audiorax? Or would you get something different. I am in the process of selecting something for my desk...
 
Top