Welcome to the LOOP Antenna Community!                                                                  Join and enjoy it!

We've been thinking of a community where we can all exchange ideas, opinions, or simply have a friendly chat about LOOP Antenna.

We rely on all members to help keep these discussion forums a safe place for people to share and view information.

So, please treat other community members the way you would like to be treated: be courteous and respectful, stay on topic, share your knowledge.

We will remove any post that includes personal attacks, swearing or offensive language, non-constructive criticism or falsehoods. Such a poor behavior will result in losing the community posting privileges.                                                                                                                                                                                         Thank you for your time and your help!

svitez
27 dic 2017

SWR discrepancy

6 commenti

I have baby loop antenna. I'm noticing SWR discrepancy between SWR shown on ATU display vs. what my Icom SWR meter shows. For example, ATU will display SWR of 1.3 but my Icom transceiver will show SWR of more than 2. When this happens transceiver power output is automatically reduced. ATU is connected to radio and then to antenna as per installation guide. There are no other devices or antenna tuners connected. Antenna tuner on the transceiver is turned off.

pa7gmu
27 dic 2017

Hi Svitez,

 

I experience the same problems that you describe. I bought the baby loop just a week ago.

I installed the loop on my garage roof about 15 meters from the house. The antenna is installed about 1.80 above the roof.

 

The loop is very difficult to tune at 40 meters. When I tune the antenna at 40 meters and work in digital mode such as FT8, this works fine. However, when I try to work in SSB mode this does not work. The SWR then varies from 1.7: 1 to more than 3. The power of the ICOM that I use is then reduced to 0 watts.

 

The internal tuner of the ICOM is off and all memories of the tuner have been erased.

 

On the 20 meter band and higher I have fewer problems, but even there I often have to tune the antenna again.

 

73 Gerard PA7GMU

pa7gmu
27 dic 2017

 

 

pa7gmu
27 dic 2017

 

 

pa7gmu
27 dic 2017

some screenshots

svitez
27 dic 2017

40 meters is the most problematic. I have to constantly re-tune to get the SWR to reasonable levels. It becomes real challenge trying to work digital FT8 on 40m because very slight change in frequency throws SWR off. This is a big problem when attempting to contact other stations, especially DX stations. I'm often left with no option but to tune on unused frequency and resort to just calling CQ.

pa7gmu
28 dic 2017

FT8 works fine for me. This means that I do not have large SWR variations over the entire band (3Khz). When I work in LSB mode at 40 meters, the SWR remains fairly constant after several tunning attempts. What is strange is that the ICOM 7410 Frequently reducing the power back to 0 watts. I have no problems with an EndFed antenna.

 

I do not understand why the power is reduced to 0 watts while the SWR 1.5: 1 and ICOM modulates very well.

 

Can someone answer this question.

 

73 Gerard

I post più recenti

Ciro Mazzoni Radiocomunicazioni

 

via Bonincontro, 18

37139 Verona -ITALIA-

info@ciromazzoni.com

Tel: +39 0458903104 Fax: +39 0458902633

 

P.IVA 03063020238

© 2014 created by Sergio Mazzoni