GHz ac frequency- Maximum "Practical" generation - Solenoid question for the experts. It's me again. Big ideas, big questions. (A quick special thanks to everyone who has ever taken a moment to answer my questions: (Bob S, bipolar, Phrak, f95toli, jambaugh, waht, Pumblechook, ZapperZ, Astronuc, mheslep, TallDave, granpa, olgranpappy, weejee, Lurch, JesseM, pervect, ) You've all really been a big help in forming my ideas and bringin them to reality.) Ok, end of "shoutout"; now for the question! Ok, I've been asking about THz frequency generation and the likes, but I'm begining to understand the difficulty generating these frequencies, especially from your responses, so for the experts: 1. What's the highest ac frequency, GHz range, that we can generate reasonably "easy" with our current technology? "Reasonably" low noise and "decent" efficiency. I hate using these qualitative descriptions rather than quantitative, but I'm hoping you'll understand. Just think "practical" on a fairly well funded DIY budget. To give you an idea of the experiment being performed, and to lead me to the next question: It involves Two solenoids fed by high frequency ac... This being the case- 2. If you have a ferromagnetic core (Iron for simplicity) in a solenoid, what is the time lag between turning on the magnet and the core being full aligned with the field? Maybe there's a formula that factor's in size, length, radius, B field generated by the wire, etc. I'm sure it's in nanoseconds. With question 2, I'm hoping to find the frequency where the change in freqeuncy outpaces the alignment of the core. Though, this is not the point of the experiment, merely the determining factor of whether the magnets I'm using will have a core or not. and last but not least: 3. Have any of you ever worked with ac electromagnets? I havn't really been able to find too much info on this. Thanks!