Summary of DX Performance Despite the horizontal polarisation and the low height 7. Without an ATU, SWR from a mismatched antenna could cause power reflection back to the transmitter; with modern solid state transmitters this causes the transmitter to reduce power to prevent heating and damage to the output stage. I wondered if there was an inbuilt voltage regulator in the control head to keep a constant drive voltage as the input power supply voltage was varied - turns out there isn't. But not having compatible CAT software available to me made this impossible. In the following calculations, all phase angles are expressed in degrees rather than radians. There were no practical issues in the reviews I read in terms of the cover - only a less than favourable impression of the look of it. A different antenna was used for
Modern solid state transmitters will automatically reduce power when high SWR is detected, so some solid-state power stages only produce weak signals if the SWR rises above 1. The T or Tee network and the PI networks also have a shape similar to the English and Greek letters they are named after. The potentiometer that forms the variable attenuator is hidden from view by the range switch. Note that the conventional control devices i. The radio operator must exercise judgement to choose among the many adjustments that produce the same impedance match. A complete balun solution is also available:
KC4GZX DIY Homebrew Projects #2
The other two controls will normally be variable capacitors. This is because the control head places a DC drive voltage for the tuning motor in the antenna head across the antenna coaxial cable. Cool fire Northfield, West Midlands. Combine this with the speech processor settings and there is a lot to be mis adjusted, you really have to take even more time to experiment. Were it not for that problem, even an antenna SWR of 2: Adjustments to microphone gain, speech processor, parametric equaliser etc.
If you intend to operate only CW, there are several very small and light options, if you are going to use 2m FM a small HT will normally suffice. Be prepared to read the page manual! In the case of the battery holder this is connected half way down the batteries — hence about volt is supplied back to the FT logic. When installing each set of wires for the first time — Secure them onto the PVC using velcro cable ties. Standing up against a wooden bookcase the minimum SWR on all bands was about 4: The insertion of a special section of transmission line, whose characteristic impedance differs from that of the main line, can be used to match the main line to the antenna. Make 2 of these and link them together via 2 cable-ties — The ends of both are then soldered in the following way: