Baluns not working

I made a 49/1 balun. I checked it several times but its not working. When I plug it in to the transceiver the receive goes right down and can't hear incoming signals but if I bypass the balun and connect the long wire directly to the coax then I can receive.

I decided to buy a balun because I thought maybe I didn't build it right but the one I bought is giving the same results and no says tuning required written on the balun so I know it doesn't have to be tuned.

Why am I not getting signals when using baluns? 

I tested another type of balun unun just to get the same result again. What am I missing? There is obviously something I'm not doing?

Hi (sorry don't know your name yet),

Sounds a bit weird. If you had just tried the one you made only, then I would of asked for a photo so we could see if we could spot a possible issue. But as you've tried a couple of others and they're doing the same it probably isn't your handy work.

Presuming it's for CB/HF? And, that you have a radio connected to it with some coax and then a long wire, be that a random or a half wave length, strung from the balun / unun? If yes on both then other than possibly some dodgy coax or coax connection, or the long wire not connected to the hot terminal of the balun / unun, struggling to think of anything obvious you are doing wrong.

Neal

It would help if you tell us what antenna you are trying to tune random or half wave and on what band(s).

Deb

A 49:1 is only useful for a half wave end-fed antenna, as that presents a very high impedance to the radio without one. 

What length wire have you got attached, and what frequency/frequencies are you trying to use?

I have lost count of how many i have made for people and never seen this problem.
I would say it was a plug on the coax that has a problem sounds like a short.

Alan Pilot wrote:

I have lost count of how many i have made for people and never seen this problem.
I would say it was a plug on the coax that has a problem sounds like a short.

I think the OP may be confused as to the purpose of antenna transformers and where to use them. That's why a few days ago I asked whether random long wire or half wave, but no response yet.

Just in case the problem isn't yet solved...

A 49:1 unun is used to transform the very high impedance (2000 ohms +- ) of a half wave EFHW antenna to 50/70 ohms matched to the transmitter.

A 9:1 unun is used to match the lower impedance (450 ohms +- ) of a 'random' long wire. However, a random long wire isn't really random. It must be of a length that is NOT matched to any of the bands you wish to use. There are websites that tell you the best lengths to use for the HF bands. Here's one: https://www.hamuniverse.com/randomwireantennalengths.html

Deb

Spider281 wrote:

Why am I not getting signals when using baluns? 

I tested another type of balun unun just to get the same result again. What am I missing? There is obviously something I'm not doing?

Because the length of the wire you're using already presents a low impedance to the radio. When you add the 49:1 balun it alters it significantly so the impedance so signals are weaker.

The idea of a transforming balun is to reduce the feedpoint impedance to 50 ohms or near that the radio wants to see or to a level an ATU can deal with.

What is the SWR without the balun?