What the hell am i missing here ?

[Buick Mackane]

Right i had 20 foot of enameled copper wire going spare and 2 x toroids so thought i would experiment making various 1:1 Baluns. Problem is into a dummy load i'm getting a higher than expected SWR. The lower bands (160m 80m 40m) seem ok but the higher bands not so good. The cores are FT-240-43 - FT140-43. Ive verified the dummy load. The patch lead. etc etc. And i know the wire is good as ive previously made a few 49:1 transformers with it....... I'm stumped!!!

By the way Ive never made a Balun before

[Buick Mackane]

Guanella Configuration

[Transwarp]

What antenna or antennas are you using them on? What's the swr reading on dummy load and then dummy load with balun connected?

If the swr goes up on an antenna when using a balun it could mean it wasn't properly resonant in the first place and was part using the coax as a radiator.


1: Check no shorts between centre and ground wires of your balun.
2: Use your nanovna and do a sweep of the bands with the balun connected only.

Amount of windings and spacing of them all play a part as well, the spacings will alter readings on the vna when you move them closer and further apart.

Ferrite mix 31 better for lower HF frequency use.

I prefer coax to enamel wire when making a 1:1 balun but that's just my preference.

You mentioned higher bands use? What frequency range in higher bands?

[Transwarp]

Have a look at this YT vid....

[Buick Mackane]

What antenna or antennas are you using them on? What's the swr reading on dummy load and then dummy load with balun connected?

If the swr goes up on an antenna when using a balun it could mean it wasn't properly resonant in the first place and was part using the coax as a radiator.


1: Check no shorts between centre and ground wires of your balun.
2: Use your nanovna and do a sweep of the bands with the balun connected only.

Amount of windings and spacing of them all play a part as well, the spacings will alter readings on the vna when you move them closer and further apart.

Ferrite mix 31 better for lower HF frequency use.

I prefer coax to enamel wire when making a 1:1 balun but that's just my preference.

You mentioned higher bands use? What frequency range in higher bands?

I have a Balun outside near the feed point of my end fed. When i place another bought balun in line with the feeder meaning there's two baluns in circuit the SWR doesn't alter

1 No Shorts
2 I don't possess a nanovna.

I own 2 x Analysers. One shows the SWR all over the shop. The other one shows it flat till roughly 15 mhz where it starts to rise. Both have been verified as working by plugging a dummy load directly into them. I have checked everything over & over. Its a total mystery

[Transwarp]

Keep it simple, connect one end of your homemade balun to a dummy load and the other to a radio with a built in swr meter or put a swr meter in-line if not, should be very little change if any in swr readings.

Use more windings also on a 240 ferrite.

Could be the wire causing problems with leakage creating impedance problems. Try some cheap rg58 on the cores instead of that wire and test, if all as should be then you've got the answer.

[Buick Mackane]

Keep it simple, connect one end of your homemade balun to a dummy load and the other to a radio with a built in swr meter or put a swr meter in-line if not, should be very little change if any in swr readings.

Use more windings also on a 240 ferrite.

Could be the wire causing problems with leakage creating impedance problems. Try some cheap rg58 on the cores instead of that wire and test, if all as should be then you've got the answer.

Plugged in to the radio 1.1 on 40m other bands high. I'm betting nobody can come up with an answer as ive rechecked rechecked and rechecked everything.

The only thing it can possibly point to is the wire. Although ive knocked up a few 49.1 transformers with it and had no issues

[Transwarp]

Unun's work more like voltage baluns so act differently to common mode 1:1's.

Like l say use some coax to make your 1:1 balun up with and test it and see what the results are.

You say you have analysers? I assume MFJ or Rig Expert type? You should be able to test the characteristics of that wire with them vs coax before using it on a ferrite also

[Transwarp]

More links for info on balun making...

[Transwarp]

And another link....

http://www.karinya.net/g3txq/chokes/

[Buick Mackane]

You say you have analysers? I assume MFJ or Rig Expert type?

A Sark 100 & MFJ Trans.

Its either got to be the wire or the cores. Although the cores worked fine when using them for 49:1 transformers. Ive ordered some other wire and will report back next week with my findings

[Buick Mackane]

Internals of a LDG Unun. Ive never seen a transformer wound in this fashion

[Transwarp]

Looks crap for a factory made one imo.

Just my own opinion enameled wire too much of a faff with inconsistent impedance, temperamental with winding spacings, different gauges give different results, this is why l prefer plain old coax.