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[TenTec] 1. Adding external line-level amplifiers to Orion 565 AUX IN/OU

To: tentec@contesting.com
Subject: [TenTec] 1. Adding external line-level amplifiers to Orion 565 AUX IN/OUT 2. Adding Stereo Speakers to Orion 565 3. Making your own AUX breakout box
From: Jerry Volpe <kg6tt@arrl.net>
Reply-to: kg6tt@arrl.net, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 19 Dec 2007 02:57:49 -0800
List-post: <mailto:tentec@contesting.com>
1. Dealing with decreased AUX gain (in and out)in the Orion 565 under Firmware 2.62a.

One of the unexpected consequences of Firmware 2.62A is a noticeable drop in the fixed audio level of the AUX Left and Right outputs (yes, both audio channels are available on the Orion's AUX connector, although the cable Ten-Tec provides doesn't give either the Right audio output or the FSK input signals so you need to buy or build your own breakout cable/box to get to these signals.... see 3. below) as well as reduced sensitivity on the AUX audio input. Depending on your applications this may or may not be an issue to you. Unfortunately it was to me, but not one that didn't have a work around.

My major 'audio level' issue involved my sound card applications (PSK31 for example). My station computers all use Delta 44 sound cards which have excellent signal-to-noise, dynamic range, etc.. but also have lower gain on their inputs and outputs than what I experience with typical consumer add-on sound cards or those built into most motherboards. Anyway, when I switched to Firmware 2.62A the Orion's AUX outs and Inputs were no longer signal compatible with the Delta sound card. I sent off several appeals to Ten-Tec regarding this but to date (months later) I haven't received any acknowledgment of this... so while I wait I decided to boost the audio out of and into the AUX connector myself. Fortunately I discovered some neat 'off the shelf' products that served my needs and took up practically no shack space.

Radio Design Labs (RDL) produces an incredible diverse line of products for use in a multitude of audio applications (studio, general purpose PA, radio station, etc.) Many of these are packaged as 'stick ups' in unusually small black plastic encased packages designed to be literally stuck where needed using velcro or double-sided sticky tape!. They have numerous configurations of small audio amplifiers just perfect to increase the output of the AUX Left and Right audio signals and to boost the sensitivity of the AUX audio input line.... all to levels more appropriate for professional sound card and other devices that the Firmware version 2.62A Orion can't supply. The new stock prices of the RDL modules can be a bit pricey... fortunately I found that they show up on auction sites rather frequently and at really nice buynow discounts. I added a small independently channel adjustable stereo 'headphone' amplifier module (about 1 1/2 x 1/2 x 2 1/2 inches in size) on the Orion's AUX Left and Right audio outputs and a small single-channel line-level audio amp module on the Orion's AUX audio input. It seems that all RDL modules run on 24 VDC so I had to get a couple of appropriate 24 VDC power cubes. I use small guage RG-176U on all RDL module inputs and outputs (with multi-wrapped ferrites on each). The results are great and as they are fully level adjustable I am ready for the next Orion firmware update. I paid $15 for one module and $35 for the other... one was NOS the other NEW.

2. Accessing both Right and Left audio outputs - amplifying to speaker output level.

Personally I tend to use stereo earphones with my Orion... helps dig out weak signals but also allows me to take full advantage of the second receiver and Binaural audio (cool... thanks Ten-Tec).... however there are times when I'd prefer to sit back without my head encased in mini speakers but still be able to aurally separate the MAIN and SUB receivers..... and use Binaural too! All you have to do is get at the AUX Audio Right and Left signals which requires some sort of 'breakout' box or cable.

Now the AUX Left and Right audio levels are 'fixed'... they don't vary with the front panel Volume controls. So whatever external audio amplifier I used had to have sufficient gain and be adjustable (with some sort of balance control too).... and be cheap... and be RF insensitive! What do you know... RDL to the rescue once again. One day an automatic alert I had set on an auction site notified me that there was a listing for a Radio Design Labs audio amplifier. I checked it out and it was perfect for what I needed. Small... separate volume controls for Left and Right... over 4 watts of CLEAN audio per channel. I spent a quick $35 plus shipping and then when searching for a larger 24 VDC power module (at least 1amp). Found one. A few days later everything was at the shack and ready for installation.... all I had to do was add two vintage Radio Shack Minimus 11 dye cast aluminum speakers and the end results were far more pleasing than what I had anticipated. Before adding the external amplifier I had been using a SoundSweet speaker on the Orion and very pleased other than not being able to tap into the stereo and binaural features without using headphones. Now with my new 'optional' stereo in the shack I have the best of both worlds. Not for everybody, but who knows.

3. Using a home-brew (or commercial) breakout box to obtain ALL signals on the AUX connector.

The Orion's rear panel AUX connector has both the LEFT and RIGHT audio signals (as well as FSK!), but as already mentioned the audio breakout cable Ten-Tec provides only has the LEFT audio signal. Hmmmmmmmm. LDG has a cool breakout box product that plugs into the AUX connector and gives RCA connections to all of the AUX signals. That LDG product is a bit pricey (about $70) so I decided to build my own. A quick look at the Buxcomm website showed a pre-wired eight-pin DIN connector/cable (just remember your resistor color codes and you will know that wire goes to what pin) for under $10. That with some RCA jacks and small plastic project box and a ferrite (love those) provide a full breakout box for the Orion for under $20.

__________________________________

What I used:

1. Radio Design Labs ST-DA3 Audio Distribution Amplifier to boost audio signals from Delta sound card to Orion's AUX Audio Input. 2. Radio Design Labs RU-PA518 Audio Power Amplifier for the stereo, room filling, speaker level output.
3. Valcom VP-1124, 24VDC, 1A Receptacle Mount Power Supply.
4. Radio Design Labs ST-SH1 Stereo Headphone amplifier
5. Pair of old Radio Shack Minimus 11 speakers.

__________________________________

Hope this is useful to someone.... and pardon the typos as it is 3am and that is what happens. :)

73,
Jerry, KG6TT

--
Ralph Jerald "Jerry" Volpe
Amateur Radio Operator KG6TT
FISTS 12304
http://kg6tt.tomorrowsweb.com
788 Chestnut Drive
Fairfield, CA 94533

kg6tt@arrl.net

510 325-7724
707 399-8838 FAX


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