Sound Card Interface

[KE5FRF]

I need advise on purchasing a soundcard interface, but before I ask, I want to discuss my problems with the one I bought before......

In October, 05, I purchased a Buxcomm Rascal GLX soundcard interface for digital modes. The price of $40 seemed reasonable, and I am on a tight budget. I recieved the interface and from the word go had problems. The furnished "instructions", though seemingly thorough, are poorly organized IMHO and don't label the input/output cables sufficiently, I guess Buck Rodgers made the assumption that you should already know how to hook everything up. (Let me say, I'm not trying to bash the product, but I'm generally very dissapointed. Just relaying my experience)

Anyway, the interface SEEMS plug and play, and I muddled my way through the instructions. I found that the modular RJ-45 mic jack cable had a connection pin bent right from the start, and wouldn't plug into the mic jack properly. I took a pocket knife and bent it back into the proper shape (as best I could). Also it was obvious where the RS-232 cable went , so I plugged it in where it goes. Now, as I remember, the 3.5 mm jack for the radio speaker was labeled clearly, so I plugged it in too. What I had left was a green and white cable. I am not at home looking at it, but one was labeled LINE IN and the other LINE OUT. In my mind, line in was supposed to be the Mic jack, and Line out was supposed to be the stereo speaker jack (of which my soundcard has two for left and right channel, I PRESUMED)

OK, I THOUGHT I had everything plugged in correctly, but nothing seemed to work. I could get PTT action, but no modulation was being transmitted from the rig. I can't be certain what worked and what didn't. I spent several hours playing with audio levels in WINDOWS and swapping the different cables. The next day, I emailed BUCK RODGERS' tech support, and got very condescending and unsatisfactory advice that implied I was a moron. I went home that evening, and FINALLY I found some combination that actually worked, but I SWEAR the white and green cables where backwards according to the instructions!! At any rate, I was happy to get my gear working, and proceeded to play radio.

Well, just a few days ago, everything went to heck for some reason. I no longer was picking up audio from my speaker jack on the rig. I played around with everything, and got it working again, but to my chagrin, the next day, without changing the green and white line in/out cables, I lost modulation on rig TX, just dead carrier when the PTT circuit is enabled through the RJ-45

So, I am fed up. This Piece'O'cr@p is not worth my time at the moment. I don't want to deal with Buck's so called tech support. I want to buy something else.

But, I'm still on a budget, and am buying a new mobile rig/antenna, which is more important at the moment. I want a plug'n'play interface at a reasonable price. So, I've been doing homework.

I just finished reading eHAM reviews for the DONNER DIGITAL INTERFACE, a **similar** product to the RASCAL interface, but where I read a lot of disgruntled comments in the eHAM review for the RASCAL and other products from Buxcomm, All I see is thumbs up for the Donner interface.

Well, all I ask for is something that WORKS, has clear and CORRECT instructions, is built reasonably well, and gets sufficient support from the manufacturer. I am not looking for bells and whistles, so though a Rigblaster Pro is something I eventually want, a good affordable product will do just fine for now.

Does anyone have added opinions on the Donner product, other products, pros/cons with the RASCAL, or general advice and/or comments?

[AC0H]

I've always used West Mountain Rigblasters.
I've heard of the Donner interfaces but never used them.
If it was buy Buxcomm or get out of digital HF, I'd get out. Too many horror stories about support "attitude" and lack of quality.

Normally I'm loathe to suggest anything MFJ but they've got to be better than Buxcomm.

[NE3R]

A sound card interface is on my list of projects to make now, I'll get flamed for actually suggesting someone home brew something.

[N5BO]

Sorry to hear about the problems with your Rascal, using one here with no problems.

The Donner is a nice interface, great price and performs with no issues. I was using one on my FT920 for RTTY, PSK31, and WSJT modes with no problems.

[N5PVL]

I made my own... Rat Shack sells the audio isolation transformers and I got my PTT Opto-isolator from somebody's dead Rigblaster.



Here's the basic PTT circuit, without the isolator.

Not much to it.

I've put together two RASCAL kits so far, for other hams... Both worked just fine.

[K8AG]

Hi,

My interface is also a Buxcomm Rascal. I agree that it was difficult to understand the documentation as you say. I have a lot (lots and lots) of experience building, designing and making things work and I still had problems.

You (they) made one crucial error in their documentation. They assume that all computer audio outputs are line outputs. That is rarely the case. Do not connect the speaker output to the rig audio in. The impedance mismatch will almost guarantee that the interface will not work. I had to go out and buy a second sound card with a line-out. Not easy to come by anymore.

The speaker out from your computer is at a very high power level and is expecting to see somewhere around 8 ohms impedance. The "microphone" sound connection on the other hand goves you probably 600 ohms (maybe 1k). This is a major mismatch from what the computer wants to see. If your computer has a line-out, use that instead. If you try to use the speaker output you will mismatch and probably cause distortion of the audio, causing your, for example, PSK31 signal to look like a lot of PSK31 signals all across the band. :{ Trying to adjust the levels will drive you batty!

If your computer does not have a line-out, you can fabricate one by putting a 10 ohm resistor across the signal as it goes into the buxcomm box. The resistor needs to be able to take 100% audio output power from the computer so it doesn't burn up. This should cause the computer audio to be undistorted. It is still high, but you maye be able to adjust it.

Hope this helps.

73, JP, K8AG

[KE5FRF]

Quote[/b] (N3PAQ @ Jan. 24 2006,13:12)]A sound card interface is on my list of projects to make #now, I'll get flamed for actually suggesting someone home brew something.

Well, you won't get flames from me. I like homebrewing.

I have the parts now to homebrew a CI-V cable, and will do it when time permits.

However, this is one particular item which i don't care to homebrew. For this particular item, I simply want something that works with good audio isolation properties.

I am sure that the Buxcomm product is a decent interface, but nonetheless, the tech support is HORRIBLE and the personalities are abismal. I simply want to deal with a "company" who backs their product up. That is important to me.

Ok, so far, I have been advised to avoid MFJ, and that Donner's product is a good buy.( I wish I had done some research on the Buxcomm.)

I already know that the Rigblaster product is good, and am considering the Nomic base model. Still, I think it is significantly more expensive than the Donner interface.

Thank you for the comments.

[KJ3N]

Quote[/b] (AC0H @ Jan. 24 2006,13:08)]If it was buy Buxcomm or get out of digital HF, I'd get out. Too many horror stories about support "attitude" and lack of quality.

*YAWN*

2 RASCALS, no problems. Ever.

Built one. Bought one pre-assembled.

Plugged in, worked from the start. Still working after 3 years.

How do you guys have this much trouble with what amounts to 2 isolation transformers, an opto-isolator, and an audio pot?

I'll give you $10 for it.

[KE5FRF]

Quote[/b] (n3jja @ Jan. 24 2006,13:49)]

Quote[/b] (AC0H @ Jan. 24 2006,13:08)]If it was buy Buxcomm or get out of digital HF, I'd get out. Too many horror stories about support "attitude" and lack of quality.

*YAWN*

2 RASCALS, no problems. Ever.

Built one. Bought one pre-assembled.

Plugged in, worked from the start. Still working after 3 years.

How do you guys have this much trouble with what amounts to 2 isolation transformers, an opto-isolator, and an audio pot?

I'll give you $10 for it.

Read my post....

I know it isn't complicated. I never said it was. However, when you plug it in just as the instructions say, and it doesn't work, something is amiss.

As I said, after plugging it in per the instructions, then playing around with every possible combination under the sun when the "right" way didn't work, and then, as if by magic, it begins to work, and later, without any change TO ANYTHING, it goes on the blink again, something is just not right.

Look, today at work I put together a new Gas Chromotagraphy lab instrument with Flame ionization detectors, hooked up the computer interface, installed integrating software, and connected peripheral automation equipment and utility gas supplies. I installed 2 fifteen meter glass capillary columns for peak seperation and programmed the test method perameters in the computer. The instrument is ready for lab use.

What does all that mean? It means I'm not so stupid that I can't install a soundcard interface. Something else is wrong here. Either the quality control standards are lacking and they sent me a defective product, or perhaps it was damaged in shipping. Nevertheless, I paid 40 bucks for it, and the fellow I bought it from could care less.

It is one thing to have trouble when you homebrew or kit build something, but to have a product act this funky right out of the box is not excusable.

[KW7DSP]

I am going to have to agree with Buck on this one. If you do not understand Line In and Line Out on a sound card, you better stay with the high end appliance interfaces of which neither of the ones you mention is. Go with a Rig Blaster or a MixW Rig Expert or Rig Expert Tiny or an MFJ interface. All are over $100. If you want to go cheep or are on a budget you need to be technically competent and computer literate.

As to your original problem. Your sound card is most likely marked Line In and Line Out. Use Line In to Line In, and Line Out to Line Out. Or Green to Green and White to White or Yellow or Blue or Red or whatever the color code is. Also some Soundcards do not have enough Line Out Drive for the radio so you need to use Speaker on the sound card to Line Out (Radio Mic In), and some radios do not have enough Drive so you use Line In to Mic on the sound card. In other words Line In is the Speaker of the radio through the device to the computer Line In ( or Mic). #Line Out is the Computer Line (or Speaker) out through the device to the radio Mic.

Buck is famous (almost legendary) for his Bad Attitude, Poor Instructions, and Quality Product at a Reasonable Price.




P.S. I might add as to my comment about Speaker from PC to Mic on Radio.

Yes there is sometimes a mismatch. The original Rascal took care of this. I think the latter do also. The transformer is the key. PC Speaker to Radio Mic is an 8 ohm to 600 ohm or 8 ohm to 10,000 ohm depending on the radio. Line In on the PC was a 600 ohm to 600 ohm 1:1 ratio transformer from the Radio. Also there was a 1000 ohm version and a some of the radio interfaces used a 8 ohm to 600 ohm between the Radio and the PC Line In. The transformer should be the impedance of the Soundcard Output used and the Mic Input on the Radio. Same thing for home brew. Radio Out at full volume will cook the 600 ohm 1:1 transformer changing its impedance, if the Rascal was a Mic In on Sound Card model. There are other combinations of input and output impedance. You need to know what they are as well as the power handling capabilities of the components. 3.5 watts or even 5 watts into a ½ watt transformer is a bad thing. Most Rascals failed because of this.