Flex 6300 Transmit Audio Issues

Cal N3CAL · February 2015

I'm not sure if this is a transmit problem with my Flex-6300? I've only owned the radio for two months now so I'm a newbie when it comes to SDR. On SSB I honestly can say I'm not happy with transmit audio so far. I've gotten poor audio reports saying I have a faint echo/raspy sounding audio and I've listened to the transmit audio myself through other receivers and can confirm the poor audio quality. It's not even close to my prior rig-FTDX-3000. I don't run any amplifiers. I've read through the "How to build a quiet station" info and have practiced and put to use all the things that can possibly cause RFI issues. I have an excellent ground system and all my cables to and from the radio have mix31 ferrite on them. It doesn't matter if I use the FRS provided hand mic or a high end Heil PR-781 or PR-22 the results are the same. I've also tried putting a W2IHY I-box in line between the mic and the 6300. Nothing changes. I'm running the latest available version of SSDR.

On the digital side using WSTJ-X the radio performs great and I don't have any problems with stations not decoding me but I do notice some spikes which I'm not sure are normal during transmit. I've provided a screen shot of my station transmitting a JT-9-1 signal at aprrox 15 watts. Do others running WSJT-X see these spikes during TX as well?

I've noticed a few others comment on this issue with the 6300 audio and wonder if I should send the rig in to Flex for a look over? Any advise would be greatly appreciated.

Cal Spreitzer/N3CAL

Dave - W6OVP · February 2015

Don't feel like the Lone Ranger, Carl. That is a common sentiment here and I share it. Amazing these SDR Transceivers can't come out of the factory with a decent set of audio defaults with setup and troubleshooting instructions. Settings are a big part of this problem.

I got nothing but bad audio reports with my 6300. It's why the guy I bought it from (who is no AMATEUR HAM) dumped it. I took the chance, and after much on the air testing and patient help solved it. Here is what I did:

1) Got rid of the factory mike. I chose the Heil HMM Handheld since I don't like headsets.
2) Set my transmit audio to: -4 -8 -4 +4 +8 +9 +6 +3.

Jackpot! Now I get nothing but rave reviews. Good luck!

Bill -VA3WTB · February 2015

You may want to read this post, It may help you...
https://community.flexradio.com/flexradio/topics/6300-echo

Jim Gilliam · February 2015

If you haven't, you should connect the radio to a dummy load. If the audio changes, you know it's probably an RF issue.

Cal N3CAL · February 2015

Hi Jim,

A dummy load was first thing I tried. I always try and set up my TX with a dummy load first. I hear no change in audio quality running the rig into a dummy load. I'm listening to the rig through a another SDR receiver. It does not matter if it's 1 watt or 100 watts the audio is poor.

Chuck · February 2015

Dave,
Along with Bills link below, a search within this community using ECO75-006 or just the word Echo will lead you to some info. You should see Bills link within that search I would think. Looks like its 6300 specific and some folks had to send their 6300 back in for work.

Regarding your JT-9 signal. I just checked mine and have about the same indications down around a level of -100 with a couple more a bit lower in amplitude.
Not sure what it is or IF its even a problem since its pretty low as compared to the main ****.
73
Chuck

Cal N3CAL · February 2015

Hi Bill,

Thanks for the reply. I've been following those posts and it seems after a long drawn out trial and error the rig in question went back to Flex for repair.

Jim Gilliam · February 2015

What kind of microphone are you using? You might try transmitting using DAX with an electret microphone and a computer and see if it improves. I don't have a 6300 but a 6500 and I get excellent reports using the electret from my portable computer. The problem, however, with the electret, is it distorts if you talk too loudly or too close to it.

Jim

Corey/ KC0YNS · February 2015

My 6300 just went back to be looked over for the same issues. You miay want to call Flex & Speak with Dudley , He was very helpful in my case.

Jim Gilliam · February 2015

I made the comment trying the electret is that it will bypass the audio stages in the Flex. If the audio improves, it might indicate that distortion is taking place in the amplifer stages of the radio.

Ken - NM9P · February 2015

Indeed, you might want to open a service desk help file. There have been a few 6300's that have needed a factory fix, referenced in the thread Bill listed above. The 6000 series are capable of fantastic audio, and yours should be no exception. Don't let this fester to the point of frustration. let FRS service help if it needs fixes, or help with adjustments if that is needed.

Ken - NM9P

Cal N3CAL · February 2015

Thanks everyone for your suggestions. I just finished talking to Flex on the phone. They are creating a service desk ticket and the radio is going back to them to get checked out.

Cal - N3CAL

N0ARX · February 2015

I would never expect a hand microphone that came with the radio to perform well. I think it's a waste for them to even send a microphone with them. I get nothing but great reports with my 6300.

Bill Roberts · February 2015

Dave, Don't be discouraged. I went through the echo/grinding noise in the mic circuit of my '6300. I aggressively addressed grounding, ferrites, etc. My echo was only apparent to locals hearing me with a very good S/N ratio. First, you're not alone. This Community is very helpful, especially with EQ values. Also, the people at Flex Radio are with you all the way. After trying to resolve things myself, I talked with Dudley several times. He authorized an expedited warranty RMA and had the radio FIXED and back to me in 2.5 weeks. Flex is a pretty unique group of people; smart, busy, in demand but always ready to do whatever it takes to make us customers successful and happy. My echo was fixed promptly. Some SSDR quirks take a bit longer. That's all part of being a pioneer1

Enjoy your radio. They can fix it!

Alan C · February 2015

Danny - what mic are you using? thx

Steve W6SDM · February 2015

As soon as I looked at the image of your panadapter, I saw RF. Been there.

I think the hand mic is included as a "starter mic". It gives you something to get on the air with and prove that everything works while you locate the proper adapter or do the wiring necessary to connect a more suitable mic.

Mic cables have got to be one of the primary sources of RF. The cables are rarely shielded. I use Heil shielded cable on my mics and it works to keep the RF out.

Cal N3CAL · February 2015

Steve,

Interesting comment. FYI, I'm not using the starter mic. I only mentioned the starter mic because my issue happens no matter what mic I use.

The panadapter image I attached is not a SSB transmission, it's actually a WSJT-X JT-9-1 transmission at 15 watts. That transmission is using the DAX. At the time of that image snapshot I had a Heil PR-22 mic attached via a Heil XLR Cable to a Behringer 802 Mixer, the mixer is connected to the Flex 6300 via a W2IHY I-box (isolation transformer) using the 8 pin foster connector on the front of the radio.

Can you please point out where the RF you are seeing?

Cal-N3CAL

Lewis Cheek · February 2015

In my case I don't think it's a rf issue, if so it has to be internal to rig. Even when connected to a dummy load and set for only a few watts output it's got VERY BAD xmit audio. I listen on my K3, as the Flex monitor function is useless in this regard. Anyone know for sure what the fix is, I really don't want to send rig to Austin for what may be a SIMPLE easy to do mod?

DrTeeth · February 2015

I don't do much phone, but have got more than a few unsolicited good audio reports from my 6300 using the supplied mic.

KY6LA_Howard · February 2015

If you lower the power on the transmit side to an absolute minimum into the dummy load does the bad audio go away. If so, it's an RF issue. Remember. The. Dummy load is only taking RF out of ur. Antenna port. RFis sneaky. It can leak out from anywhere. Such as ur mike cable or ur ethernet cable or ur power cable.

Steve W6SDM · February 2015

Cal,

When I had my RF issues I was seeing spikes much like the ones on your display. I saw them both on phone and CW, didn't try it on digital modes. Both my SSB signal and my CW both sounded raspy. The audio was getting in primarily through the mic cable but also through the lead to the powered speaker. With the mic cable, I changed to shielded cable. With the audio, I put on an isolation transformer and that cured it.

It's possible that something else could be going on. BTW, I use a Heil PR 781 and sometimes a refurbished D-104 with the Heil replacement element for SSB.

Cal N3CAL · March 2015

FYI, I sent my 6300 back to Flex last week to be checked out for this issue. They received my rig on Friday and today (Monday) I just received an email from Flex confirming the issue and that the following was done by Flex Service Department: "Applied ECO 75-1006, Ran tests, Passed tests". I'm not exactly sure what ECO 75-1006 is but my rig is on it's way back to me. Many thanks to Flex doing such a quick turnaround which I'm grateful for! That's great customer service! My best guess is that ECO 75-1006 has something to do with the radio's internal grounding.

Cal/N3CAL

W7NGA · March 2015

Cal,

Please report back with us about your observations vis-a-vis the repair. Echo on Flex signals is so prevalent you can hear discussions about RF ingress and echo on most every band. There would appear to be a hyper-sensitivity to RF currents that in many installations ferrites and grounding schemes cannot vanquish.

dan W7NGA

Corey/ KC0YNS · March 2015

modify if necessary the grounding point of the mic input circuit to improve noise rejection. There is no cable involved; the circuit is on the TRX board.

Corey/ KC0YNS · March 2015

Dan, Look through these:https://community.flexradio.com/flexradio/topics/6300-echo

N0ARX · March 2015

Alan I am using a Heil PR40. I am really happy with it too.

Bill Roberts · March 2015

Agree. That fix took care of my echo and fan noise. The local who complained about my transmit audio now praise it. Flex cheerfully stands by their products.

W7NGA · March 2015

Corey, I am listening to you on 17-meters and you most definitely have RF ingress issues that are tearing your audio. You've just received your 6300 back from the factory so I thought you might be interested in a report.

With additional listening, you have a lot of energy in the unused sideband and could be overdriving your amplifier if you are using one. A very strong signal but something isn't linear.

73's, dan W7NGA

Corey/ KC0YNS · March 2015

Dan. Thank you for listening & Letting me know... I am using a EQ Plus & 8 band EQ from W2IHY Driving a Ameritron ALS-600 Amp. using the outboard EQ & turning off the Flex EQ, also have the 20Db off. Using settings on the EQ given to me by a 6300 & 6500 Flex owner, I've tried several different things including other Mic's. Originally tried a unbalanced Heil HM-10 directly into the Flex 8 pin foster, That proved not to work, Also tried the hand mic without success. Just got off the phone with Flex, Spoke to Matt & He's going to send me a new Heil cable to try with this PR-781 directly into the 8 pin foster bypassing all the external EQ equipment. If that doesn't work, I'm committed to Flex, Their service is second to none & If I'm unable to achieve the quality of audio with this 6300 it will be traded in for a 6500, I'm thinking that would solve my problem. By the way only driving the amp with about 55 watts. So I know something isn't correct. But what? I've had this station torn apart working on this & that putting 43 ferrites on every cable I could. Thanks again, I do appreciate your critique.

Ken - NM9P · March 2015

Mix 31 is better for HF. See DX Engineering. But there must be some other ingress of RF. Yes, take the external audio gear out of the equation in order to isolate the problem. Once you get it fixed with the mike only, you can add that stuff back into the audio line.

Jon_KF2E · March 2015

The most important place to put the ferrites is at the feed point of your antenna. You need about 18 inches worth to do the job. Also, Ken is right mix 31 is better for HF frequencies.

Jon...kf2e

Flex 6300 Transmit Audio Issues

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