I'm into CB'ing and have just got myself a 1KW Zetagi DL61 dummy load for testing various amplifiers, etc'. My Zetagi DL61 dummy load shows 48 ohms when checked cold/unused with an ohmeter, but when it heats up after use, checking it again with an ohmeter, the resistance can go as low as ~35 ohms. Is this normal? Even though the resistance/impedance of the dummy load varies so much, the SWR stays under 1.1:1 throughout HF, and under 1.3:1 at VHF (2M band). SWR stays steady at these levels despite such aforementioned drastic changes of resistance/impedance over the duration. Surely an impedance/resistance of ~35 ohms would exhibit a SWR of around 1.6:1 or thereabouts, so am I missing something? I say this because a 100 ohm or 25 ohm impedance would be a 2.0:1 mismatch. Can anybody shed some light on why I'm seeing no mismatch at 35 ohms when heated, and also, is it normal for this "big resistor" or similar to drop in value when heated up? Here is what's inside my dummy load. Many thanks.