Flex 6300 Transmit Audio Issues

Corey/ KC0YNS

Never had any RF issues in my shack with any other HF rigs sitting in the same location. My bench is 16 foot long with four operating positions. I'm thinking its in the external EQ gear which I used because of not having the correct cable. 3pin XLR to 8 pin foster. Once I get the new cable I'll take out all the W2IHY equipment & see what happens. It may also be coming from the current cable that's in the boom, The booms with cables were given to me by a AM/FM broadcast station owner because of an upgrade. I did cut one side of the cable separating grounds. I'll let everyone know what happens when Matt sends me the cable... Thanks to everyone helping me.

Norm - W7CK

N0ARX,

Can you tell us what settings your using on your Heil PR40?   It has taken me forever to get mine dialed in so that it sounds "presentable".  I'm not talking great but just presentable.....

It would be nice to have a small place to put files such as microphone EQ settings, instructions for DAX, grounding, etc., so that we can all reference them!

Norm - W7CK

DrTeeth

@ Jon

Does every ham have different opinions on where to place ferrites? I have seen several photos of ferrites attached to the feeder where it enters the rig.

Is it like they say about dentists (my day job) - you can go to 10 different dentists, get 11 different opinions, and they will all be right?

I have an RFI issue I need to tackle soon.

May I pick your brains? If one has a clip on ferrite and one wishes to make several turns of the wire through it, does one keep the direction of the turn the same on both halves or is it best to reverse it on the second?

TIA

Jon_KF2E

Hi Guy,

What in ham radio doesn't have lots of opinions? As for ferrites, I say put them at the source of the RF. The reason we use ferrites on coax is to remove the RF from the shield. That said, if you want to remove RF from your shack and it's coming in over the shield, why not remove it as far from the radio as possible? If you put the ferrites on the coax as it enters your radio you will likely still have several feet of coax radiating RF in your shack as well as a bunch close by.

As for your question...I don't think it matters. Wrap what you can on the core and still get it to snap together.

Jon...kf2e

DrTeeth

Thanks Jon

Jim Gilliam

The reason to put ferrites at the junction of the coax and the antenna is to prevent currents on the inside of the shield as they enter the antenna to not also enter the outside of the shield. The RF currents are "dumb" and want to travel wherever there is a conductor. Putting the RF beads at that point "chokes" them off and presents a much lower impedance to the antenna where most or all of the currents will go for radiation from the antenna and not the coax. Also, the better of both worlds would be to put them at the antenna and at the junction of the transmitter output.

DrTeeth

Thanks Jim

DrTeeth

Hi Jon and Jim,

One trip up on the roof later, and ten ferrites clipped onto the feed line seems to have done the trick - not that I wish to hex things by being optimistic too early. Looks like I can move over to my main PC at long last. Will get some hefty downlads started later and see if all is well - RFI used to disconnect my PC from the network (and the radio of course).

Jon, bit short of your 18 inches, but if it works...right ;-).

The only slight downside is that all my (manual) ATU settings have changed, they had become quite automatic.

N0ARX

Norm, are you asking what EQ settings I am using on the Flex?

Jon_KF2E

Well, 18 inches isn't exactly scientific. Maybe in metric is equals 10 ferrites?

As you say...if it works it must be right.

73,

Jon...kf2e

Jim Gilliam

There are no set minimum number of ferrtes. The more the better, but there comes a point of diminishing returns. The number of beads needed depends on the impedance of the outside braid. There are many variables that affects this impedance including length to the transmitter, local ground conditions, proximity to surrounding objects, and the dielectric constants of the coax itself. It is possible the impedance looking into the outside braid could be very high on some frequencies and very low on others. The choke, hopefully, will supply enough high impedance in the range of operational frequencies.

Norm - W7CK

N0ARX Yes.  Here's what I had to set mine at in order to get acceptable audio out of my PR40.  It took me forever to come up with this setup and I had help from several people over the air as well as folks at Flex.

63= -10

125 = -10

250 = -10

500 = -4

1k = 2

2k = 9

4k = 10

8k = 10

Low Cut TX: 100, High Cut 3200, Balanced input into the back of the rig

Microphone is set with +20dB

PROC = DX+

Mic Gain = 90

DrTeeth

I am going to be applying more ferrites around the shack in the near future. So far, testing is 100% okay so will be moving over to my main PC and a dual monitor setup very soon. The only known remaining issue is that the power light on my USB 2 hub goes out during TX - yet to see if connectivity is affected.

KY6LA_Howard

You can never use too many ferrites. When in doubt add more

Dale KB5VE

I see a lot of stations with rows of ferrits and to be honest I do not believe Flex would sell a radio you had to do this wit. I believe there should be more effort to find wher the rf is comming from. It's issue is jumpers are they properly made I will not use the hamfest find molded cables. I connect everything from radio to the amplifier with rg 223 50 ohm a little larger than rg 58 but is double silver shielded and was developed for making probes for nuclear test instruments . A little pricey but great stuff. From the amp on I use ,il spec rg213 solid dielectric no foam! Before hooping up I clean all the pl239 and pl259 threads with a brass brush and put adopt of mineral oil on the threads. When tightening up do as tight as you can by hand then a 1/8 to 1/4 turn with plyers on all fittings. Then single point ground if you still have rf issues trace feed line and then the antenna. I have a large ferrit on my pr40 as it goes in the back of the radio. I can run 3 kw only as a fast test with no RFI anywhere I have taken the ferrit of no RFI.

N7CXI

This horse has been well beaten, but I came across something I haven't seen mentioned here yet.
In my case I attempted to integrate the 6300 into my station using a ASTRON SS-30M switching power supply. I had nothing but trouble with TX audio - raspiness and other nasty reports. Even though I ran the radio directly into a dummy load and said so repeatedly, I received lots of counsel on proper station grounding, the application of Mix 31 ferrites, etc. The counsel was good, but unfortunately not relevant to the problem.

Out of desperation, I finally pulled the SS-30M and put in a VS-35M (35A metered, adjustable supply) I had on the shelf. Problem instantly solved. I have no idea whether this "mystery fix" will apply to you, but it's something to try when you've tried everything.

HTH,
Jim N7CXI

KY6LA_Howard

All switching supplies generate RFI. Some of the better ones allow you to tune the RFI out of the reciver passband.

In this case, the RFI is obviously getting into your audio /Transmit chain. This is why I alway recommend against using Switching Supplies if you want a Quiet Station

Dave - W6OVP

A good useful comment, Jim.

I use an MFJ-4230MV adjustable, both before and after solving my 6300 audio troubles. So it was not the problem. But it's small, lightweight, and silent, and seems to have avoided the other problems MFJ power supplies are reported to have, so I bought a second one as well for another rig.

 -Dave W6OVP

Corey/ KC0YNS

I've been having audio issues with my Flex 6300 for awhile now, Although its close to being resolved. Yesterday one of my Pre Net fellow Ham's told me he was hearing AC ripple on my signal & asked if I could change supplies which I did. Afterwards, he and others told me my audio improved & the ripple was no longer present. The supply was a Astron Rs35m its not a switching supply. . Just thought I'd pass that along. Haven't had time to put a scope on the supply to double check it yet.

KY6LA_Howard

Corey

I seem to recall reading that the RS Astron's can have failing caps that cause ripples
Definitely worth looking at it UNDER FULL LOAD on a scope

Rich McCabe

Corey, haven't caught you on the air yet but in summary are you saying your audio improved after getting it back from flex with the update and then the rest was removed with the power supply change? So a combination of the two?

George KF2T

Just a quick two cents....

Yes, ferrites help, and in some situations they are essential.

BUT

If adding a lot of ferrites to the antenna meaningfully changes the problem, and causes tuner settings to change - generally there is a problem with the antenna. Not necessarily that it's "wrong" or "bad" - but just there is something not quite straight that can be improved by changing placement, grounding, feed line quality, etc. 

Of course, there is a limit to what one can do. That said, look for things that CAN be done. An effective antenna will minimize RF in the shack, etc. Ferrites can mask a problem, but leave you with an inefficient setup. It's a balancing act. Improve the installation as much as possible, then add the chokes. If the ferrites are getting warm during operation, there's more work to be done. 

By the way, I am a fan of ferrites on a lot of things. All my video, DC, audio, and USB lines have them. Noise pickup and radiation are real issues that we all face.

Dave - W6OVP

Maybe FLEX should sell "factory approved" power supplies or at least have a list of specific recommendations since they are such an important part of the installation.

N7CXI

Or perhaps just include the power supply in suggested troubleshooting.
I still haven't figured out why (in my case) the SS-30M causes problems with the 6300, but not with any of my other rigs. The issue isn't self-generated RFI, but some weird kind of ground loop not present with the analog supplies. I suppose I'm too lazy to investigate further...

Jon_KF2E

I used an SS-25 without issue...go figure.

Jon...kf2e

DrTeeth

Hi George,

I just have an end-fed, used for all bands; one end attached to the house and the other to a tree 30M away. Not too high off the ground either. Once the British weather improves (PMSL) I will run a counterpoise or two, parallel with the antenna itself.

That is my permanent solution. I do have enough room to put up a full-sized half-wave dipole for 40M, which is a project for the future as well as other antennas to play with.

Before the toroid fitting, the main PC would disconnect from the network - not a good thing for an SDR radio. All is well on that score now and more toroids will be added now that I have learnt a bit more about how to place them.

The only think that misbehaves now (apart from me ;-)) is one of my USB2 powered hubs which can be swapped out for one that behaves if I cannot tame it.

Cheers

Guy

Corey/ KC0YNS

Rich, It's really hard to say, I've worked all the different angles I know, moved settings on the outboard EQ & The settings on the Flex. Bottom line my Ham friends that I've talked to for years keep telling me something still doesn't sound correct. They say its much approved from where it started and it's good audio, But not as great as other rigs I've used on the air. With that said. Matt at flex is sending me a XLR to 8 Pin foster cable, I'm going to take all the outboard equipment off and try using just the PR-781 Heil directly into the radio & use the Factory settings listed in the Flex menu, & Tweak if necessary. If that doesn't prove to work, I'm sending this 6300 in for a 6500....I just don't hear of  audio issues with the 6500, I'm not thrilled with the idea of spending the additional money. I feel you should be able to get good results with the money spent on a 6300,  But I'm sold on Flex receive & The great customer service.   Would be nice to make a contact with you....Thanks for your interest,  I'd also be curious if anyone reads this and is running a Ameritron ALS-600 Amp, How many watts on the Flex are you driving it with to get the 500-600 watts of RF out?    

Jim Gilliam

I have heard 6300's that I think sound every bit as good as the 6500/6700. Give it a chance before throwing in the towel!!

Jim, K6QE

Tim - W4TME

Tighten all the screws inside the PS.  If they are lose, it can cause noise.

Lewis Cheek

This tread is starting to sound like EARLY ICOM days, where all the talk was about re seating screws, unplugging and re seating connectors, etc. I don't know what the solution is for bad xmit audio, and sounds like neither does Flex. My poor xmit audio seems to change daily. At some point Flex will resolve, and until then I'll just work cw. FWIW: bad xmit audio is ONLY with the 6300, nothing else, so that's makes me think it's the radio.