Terms of sale


The total current price of the kit including any other material which can be downloaded from this site is shown in shopping cart. Each kit content is clearly described in the product description section of this site

Prices are subject to change without notice.

Remark 1: The total price of the Product is formed from the following components: 50% part for the hardware (which is physically send and this price is declared in the parcel) and 50% part for the documentation (including software if such exists) which can be downloaded from this site. The hardware, documentation and software are inseparable parts.
Remark 2: Bulgaria is a member of the European Union and there are no additional taxes for EU members since we are not VAT registered. Domestic taxes for the rest of the world (if they exist) are the entire responsibility of the customer. We are not a company with paid personnel and for the moment there is no VAT registration. We do not issue invoices to corporate clients. Personal invoices are included upon request.

Order and Payment

The orders with payment (kit total price plus delivery expenses, no additional Pay Pal fees) should be performed via Pay Pal system through “Add to Cart” button. There is no price discount when buying multiple kits and they will be sent as separate packages each with the corresponding shipping prices. The reason is that we are sending kits as a “small parcel”. When the weight and price increase above certain limits the “normal parcel” category must be used which is more expensive since the minimal price is for 2 kg weight. There are also customs alleviations (for non EU countries) when the price of the parcel is below certain limits. If you want to use other ways of delivery or to send all items into a single parcel you should send an email to info@active-antenna.eu and wait for the confirmation from us. Usually in this case we will send a Pay Pal invoice for the due payment. If you want to use other ways of payment (e.g. bank transfer) we will send you a proforma invoice.


The price of shipping of a single kit as a “small parcel” (airmail, with priority, not insured, registered mail) is shown in shopping cart. This price is “flat rate” and is the same all over the world. For multiple kits orders we will send each kit as a separate parcel.

This is the standard international post-office service. The parcel usually needs between 5 and 15 days to arrive for Europe and slightly more for the rest of the world. After the dispatch we will send the parcel tracking number by an email to email address obtained from the PayPal order. Some customers do not use this address for correspondence and rarely read it. Please check your email content after the purchase.

We can track only that the parcel has left Bulgaria. Check at http://www.track-trace.com and enter at Post/EMS field your tracking number. The message “Insert item into bag (Otb) ” means that the parcel is ready to be loaded on the airplane to certain destination. This is the last message (with date and time) from this web site. Our commitment for the shipping ends at this point.

In some countries the incoming parcel can also be tracked on the website of the National Postal organization so the next step is to check at your national post site for the arrival. Probably you can do that also on the site of http://www.track-trace.com . Choose the destination country from the drop down country list.

All expenses due to any problem with the post office service after the parcel has left Bulgaria are to the customer. In the case of lost parcel we will provide you with proof that the parcel was delivered and with the tracking number that it has left the country – otherwise we will send another kit. There will be no official commitment by us for lost, damaged or delayed parcels after the parcel has left Bulgaria but in any case we will try to solve such problems in informal ham spirit style. If someone wishes to use courier service that can be negotiated with emails to info@active-antenna.eu. Currently the orders are dispatched from our office within 7 working days.


The return of a functional kit is not possible. In the case of malfunction due to a production defect the customer should inform us with an email to info@active-antenna.eu with a brief description of the defect. If the case is a production defect the kit can be returned at the address specified in our confirmation email. The cost of the return shipping of the repaired kit will be at our expenses. The above will be possible within 90 days after the day of the payment. We believe that 3 months is a sufficient period for the most of the production defects (if there are any) to manifest themselves. We are not specifying the usual commercial guarantee period since we are not a company with paid personnel. The kits are low priced and it is difficult for us to give to the customers the usual commercial guarantees. This limited guarantee does not apply to the kits which are visually damaged or repaired by the customer. We will do our best to solve all arising problems in informal ham spirit style.


The SDR-TRX Switch kit (referred to as the Products) is not intended for professional use or other responsible applications. It is a hobby projects and it’s intended to be used by the amateur radio society. The specifications data are based only on measurements in the designer’s laboratory and model calculations. They are made on random production samples. The designers and producers of this Product will make all the necessary efforts to ensure that the production fulfills the above mentioned specifications. We do not guarantee that the documentation of the Product is free from unintentional errors. Any damages or losses direct or indirect caused to any third party by using the Product and its documentation is entirely user’s responsibility. The antenna, the cable and the power supply built or supplied by the user should fulfill the requirements of the respective safety standards and regulations.


These Products and associated documents and programs are copyright © of SignaCor EOOD and Chavdar Levkov (LZ1AQ amateur callsign). Commercial use is forbidden without written permission from the copyright holders. Any citation of the text, schematics, photographs and other related materials from these documents can be freely distributed for non-commercial purposes with requirement of written citation of the sources which are www.active-antenna.eu or www.lz1aq.signacor.com