Hum in tx

[kk4fpx]

I have been told by two stations that I have a bad hum in my transmissions.Any ideas?

[KJ3N]

We're going to need a lot more details. List of equipment, etc.

[kk4fpx]

I have a Radio Shack HTX-10,25 watts.It's hooked to an inverted v antenna,and hooked to a MFJ 4312 powersupply.

[NQ6U]

I have a Radio Shack HTX-10,25 watts.It's hooked to an inverted v antenna,and hooked to a MFJ 4312 powersupply.

My first suspect would be the Mighty Fine Junk power supply. Can you try powering it from a car battery or another power supply?

[KG4CGC]

Yes. Test it on another power supply. If that fixes it then you'll need to change the big caps in the PS. This can be dangerous as you'll need to make sure they are completely discharged. Yep, they pack a smack that could kill you. Don't ask me how.
A band-aid that might work for a while would be to ground the PS and radio separately.
As for the antenna, some people are for grounding the shield leg, some are not.

[kk4fpx]

I was just talking to a station on California.He told me to put my finger on the mike plug . He said that it worked.next?

[KG4CGC]

I was just talking to a station on California.He told me to put my finger on the mike plug . He said that it worked.next?

Ground the radio and PS separately.

[kk4fpx]

Not sure how to do that.

[KG4CGC]

Not sure how to do that.

http://www.hamuniverse.com/grounding.html

[kk4fpx]

I saved the site.I'll go over it later.Thanks

[KC2UGV]

I saved the site.I'll go over it later.Thanks

After you read over that, and are pretty sure you understand most of it, go here: http://www.w8ji.com/station_ground.htm

[NA4BH]

Question: Do you have a tuner attached? What's your SWR?

[kk4fpx]

No tuner and I do need to get swr checked.I have a friend thats coming over to do just that.Also I'm bone up on station grounding before posting anymore for a while.

[N8YX]

A lot of power supplies - older linear designs, especially - don't keep their chassis at true "ground" potential. If the rig itself isn't grounded correctly (thereby introducing ground loops on the shields of the peripheral cables) you'll get this problem.

Start at rig first and make sure its chassis is connected to a good (water pipe or equivalent) ground.

[kk4fpx]

Anyone read this?http://www.eham.net/articles/21383

[NQ6U]

Anyone read this?http://www.eham.net/articles/21383

Interesting, and I think he may be on to something; it's good to ground things to a common point without daisy chaining (to avoid ground loops) but some people do go overboard.

I ground all the ground-able equipment in my shack to a wall-mounted bus bar that's connected to a water pipe through an 8' length of the largest diameter multi-strand wire they carry at the local Home Despot. It's also bonded to the mains electrical system ground (the green wire) for safety. Some of the real grounding freaks would say that's inadequate but it's the best I can do and I've never had any problem that's traceable to a grounding issue.

[KG4CGC]

We have a lot of iron in our soil here so getting a solid earth ground isn't a problem.

[NQ6U]

BTW, do not connect your computer to the common shack ground! You're just asking for trouble. Ask me how I know...

[kk4fpx]

I think I found the problem,won't know for sure until the liquid tape dries and I get back on the air.The mic conection had a bare wire very neat the metal conector.

[kk4fpx]

I really need to check my spelling before I post.LOL

[KG4CGC]

Very neat.

[KJ3N]

I ground all the ground-able equipment in my shack to a wall-mounted bus bar that's connected to a water pipe through an 8' length of the largest diameter multi-strand wire they carry at the local Home Despot. It's also bonded to the mains electrical system ground (the green wire) for safety. Some of the real grounding freaks would say that's inadequate but it's the best I can do and I've never had any problem that's traceable to a grounding issue.

And I think you went overboard once you got past the buss bar.

I'm with WIK on his "no station ground" thing. Other than the 3-pronged AC outlet, there's not a single extra ground of any kind in my shack. There's also nothing grounded outside the shack, for that matter.

I run 5 wire antennas, one 15m beam, and an old R-7000 vertical here. Except for the R-7000, everything goes to an Ameritron RCS-10 and then into the Palstar AT-1500DT. I use an AL-80B amp and have a Dentron DTR-2000L as a backup. I use an Alpha-Delta Delta-4B switch to change radios between the K3, IC-7000, and an IC-703. There's not even a buss bar in the shack.

There's not a single trace of RFI in the shack. Depending on what band I'm on, what antenna I'm on, and if I'm running the amp, I get into either the PC speakers on her upstairs computer (generally 40m), the PC speakers on my upstairs computer (usually 75m), or the speakers hooked to the surround sound system (20m and it's extremely light). If I'm running 100 watts (which is most of the time), there's nothing to tell that I'm on the air.

No amount of "grounding" in the shack will fix the above issues, because they have squat to do with grounding. These are all cases of fundamental overload and cheap-ass design, especially the PC speakers.

Just because "the book says so", is a lousy reason to add "grounding" to your equipment. You'll often introduce more problems than you solve. Second floor shacks are a prime example of this. People try to run a "ground wire" from the shack to a ground rod in the dirt. Usually, this wire is around 16 feet long. For those of you playing the home game, guess what else is usually 16 feet long? Hint: Most second floor shacks that try to do this, usually have trouble on 20m.

I'm a BIG fan of KISS (not the band). Only when I find a problem, do I start adding things to the shack equipment. Usually, that entails adding toroids to things outside the shack, not "grounding".

[kk4fpx]

very near....,I just talked to Puerto Rico on the 10 meter, wp4onw said he heard no hum.

nope not fixed.A Colombia station told me I was very hard to hear because of the hum.Crap!

[kk4fpx]

kj6bso wrote:My first suspect would be the Mighty Fine Junk power supply. Can you try powering it from a car battery or another power supply.
I'm not saying it's fixed yet but....Hooked it to battery and got no reports of hum.In fact got 59's from Paraguay and Chile.

[KC2UGV]

Interesting, and I think he may be on to something; it's good to ground things to a common point without daisy chaining (to avoid ground loops) but some people do go overboard.

I ground all the ground-able equipment in my shack to a wall-mounted bus bar that's connected to a water pipe through an 8' length of the largest diameter multi-strand wire they carry at the local Home Despot. It's also bonded to the mains electrical system ground (the green wire) for safety. Some of the real grounding freaks would say that's inadequate but it's the best I can do and I've never had any problem that's traceable to a grounding issue.

Inadequate? About the only thing I'd change is make it a braid connection. But, what do I know :-?

[K7SGJ]

I think I found the problem,won't know for sure until the liquid tape dries and I get back on the air.The mic conection had a bare wire very neat the metal conector.

Liquid tape? I don't think I'd use that in a mic connector, or anywhere else for that matter. If the wiring in the connector is that messed up, clean off the connector, cut and strip the cable and start over. Just be sure to note which color goes to which pin on the connector, and, if you're not sure, check the schematic or an online site that has the information. Get some heat shrink tubing to cover the connections, and do it right, otherwise I can guarantee you that the problem will return and bite you in the ass again. I don't know how comfortable you are soldering, so get some help if you need it, and practice, practice, practice. It's a skill you will use time and time again in the hobby. Also, some radios have voltages at the mic connector for TT or other purposes, and a wild wire in the connector can cause some significant damage so be careful. Good luck!

[kk4fpx]

If the problem comes back I'll get someone to come over and repair it right.My eyes are not as good as they once were and my hands not as steady.

[K7SGJ]

If the problem comes back I'll get someone to come over and repair it right.My eyes are not as good as they once were and my hands not as steady.


Many of us can relate....

[KJ3N]

Many of us can relate....

In the last few years I've begun to relate. The hands are OK, but I can tell my focal point has shifted.

[KG4CGC]

And if it is your PS then the caps need changing.

[WØTKX]

In the last few years I've begun to relate. The hands are OK, but I can tell my focal point has shifted.

Marraige will do that to a person... :whistle:

[W7XF]

Hello.

That hum you hear is coming from the APU on my pink Bell 47 helicopter. :lol:

Seriously...try this: pick up a few large electrolytic caps at RatShack, and hook them to the output
Terminals on the PS. If hum is reduced.or gone, then you know you need to.replace the.caps.

[NQ6U]

Hello.

That hum you hear is coming from the APU on my pink Bell 47 helicopter. :lol:.

Or maybe his radio just doesn't know the words?

[N7YA]

I havent visited eHam in years. I used to be a regular contributor there. As you can see in the comment section, it was nothing more than a place for the sociopathic, angry, lonely hams to attack anyone who violated their geekdom. Didnt care for the breed over there, of course there were good hams, but wow...just read the comments.

[N8YX]

I havent visited eHam in years. I used to be a regular contributor there. As you can see in the comment section, it was nothing more than a place for the sociopathic, angry, lonely hams to attack anyone who violated their geekdom. Didnt care for the breed over there, of course there were good hams, but wow...just read the comments.

And for that I blame their moderation...rather, the lack thereof. There are quite a number of the 'fragile elite' in attendance and the staff is extremely lax and/or tardy in dealing with the inevitable spate of personal attacks which accompany almost any heated discussion.

[N7YA]

I thought it was run by bots who simply keep the place operational. Its long been a vile and insecure place.

[kk4fpx]

I've been on forums like that,and didn't take long to drop them.I like the comraderie of this forum.

[N7YA]

This one is great, and its the only one i come to.

[KA9MOT]

Hell... I thought this about a Hum in Texas........

I guess I'll go read it now. :-D

[KA9MOT]

If the problem comes back I'll get someone to come over and repair it right.My eyes are not as good as they once were and my hands not as steady.

I've become best friends with a magnifying glass and a LED Flashlight..... :(

[KG4CGC]

I've become best friends with a magnifying glass and a LED Flashlight..... :(

♪... deep in the hum of Texas ♫

[KA9MOT]

I recall vividly a hummer I once got in Texas.........That one led to a 4 year relationship and a couple of kids........

[NQ6U]

I recall vividly a hummer I once got in Texas.........

Ah-nuld "The Governator" Schwarzenegger really enjoyed his hummers.

[ki4itv]

I'm with WIK on his "no station ground" thing. Other than the 3-pronged AC outlet, there's not a single extra ground of any kind in my shack. There's also nothing grounded outside the shack, for that matter.



I'm a BIG fan of KISS (not the band). Only when I find a problem, do I start adding things to the shack equipment. Usually, that entails adding toroids to things outside the shack, not "grounding".

Same deal. So no heroic grounding efforts, Free floating here. KISS is good.
My station is not particularly complicated though and I haven't noticed any issues that hint at the need for a separate station ground.
So no need to suffer the minutia of what would seem to be a very subjective topic in the ham world.
YMMV

[wa6mhz]

I'll be going through AMARILLO in a few weeks. I'll stop and LISTEN for the Hummmmmmmm

[KG4CGC]

I'll be going through AMARILLO in a few weeks. I'll stop and LISTEN for the Hummmmmmmm

It's strong in El Paso but in Austin ... whew! That's a different story.

[wa6mhz]

This is the HUM I thought folks were talking about. Very loud in Taos, New Mexico.
http://en.wikipedia.org/wiki/The_Hum
http://www.qsl.net/w5www/taoshum.html

[kk4fpx]

Don't know if it will last or not,but I was told the hum might be caused by the tone burst thats programed in the FM.I checked and turned it on and off.I talked to two different states tonight and they told me no hum and I was very clear.

[N8YX]

Don't know if it will last or not,but I was told the hum might be caused by the tone burst thats programed in the FM.I checked and turned it on and off.I talked to two different states tonight and they told me no hum and I was very clear.
Yep...CTCSS will get you every time, especially if you've set the rest of the audio chain up to emphasize the bass portion of the spectrum.

Glad you figured it out.

[KG4CGC]

DANG! I would have never thought of that.

[kb2vxa]

In Britain, the most famous example was the Bristol Hum that made headlines in the late 1970s.

The stars are spinnin every Friday night
They hum the greatest if they do it right
But it's the latest it's the greatest sight to see
The kids in Bristol are sharp as a pistol
When they do the Bristol Hum
Really somethin when they join in jumpin
When they do the Bristol Hum