Dear Andy, The quantity and ingenuity of the circuitry in the 856(0-5) series of spectrum analyser remains a source of wonderment to me, getting on for 40 years since that series started. Amazing what

Dear Andy, It is a popular myth that stainless steel is not magnetic. Of the four commonly used classes- Martensitic, Ferritic, Duplex and Austenitic, only annealed Austenitic is non-magnetic. However

Dear Robin, A quick look at the skin depth in stainless steel will tell you that steel without suitable plating is not a great material to make Yagis out of. Galvanised steel, if the process is really

Dear Andy, These harmonic mixers/multipliers use constant voltage bias- in the SAs, the bias depends on the harmonic band in use. My recollection of the 8560 series circuit is that there is a D to A t

Dear Neil, The 3mm cut is much shorter than the length of the compression sleeve, for top hat connectors, so there is no compromise to waterproofing. That said, I would never have any connector pair o

Dear Neil, I use RG142, or rather the current MIL version of it, and find that it fits standard top-hat style connectors with no difficulties and good return loss up to 8GHz, provided that a 3mm line

Dear All, Beware the transverter store and similar cheap 70cm transverters. My sample was unstable on transmit with big (-15dB) drive dependent spurious oscillations across a wide range of frequencies

Dear Conrad, Last time I went through the bother of measuring it, I got a value of 200K in most directions- this was over land, rural environment. If you have the good fortune to be overlooking sea, s

Dear All, Just one detail to add. Noise figure of cable equals its loss only if the cable is at standard noise temperature, To- 290K. If the cable is at a different temperature, the noise figure is 10

Dear John, Have had that problem with the DB6NT 23cm transverter. In my case it was a cracked ferrite on the oscillator board that had moved the free running frequency to the edge of locking- as the c

Dear Chris, Thanks for the post. I want to buy a good quality 0.6m offset feed dish for satellite use to replace the present steel one I have, which is rusting. Can anyone suggest a brand/source? Rega

Dear Andy, How I remember the 707 and 757 SAs. Cobbled together with a Tek display, Telonic stepped attenuator etc etc. I expect they were developed for a DoD contract that, for some strange reason co

Dear All, One material not to use is perspex. Loss tangent at 1MHz is 0.014- enough said. Regards, Alwyn _____________________________________________________ Alwyn Seeds, Director SynOptika Ltd., 114

Dear All, The problems with BTInternet and other ISPs and their mail policies are the reason I own my own domain and choose a hosting service that does what I need not what they want. When I have prob

Dear All, Yes, the pot arrangement on the PSTs is not a great piece of design. I replaced the original pot with a plastic shaft Bourns type and took great care with the alignment of the assembly to av

Dear All, The concern for me is if full licence amateurs are NOT permitted to self-certify. Consider what has already happened with electrical installations- although I am considerably professionally

Dear Conrad, The Teuchels are screened. Regards, Alwyn _____________________________________________________ Alwyn Seeds, Director 114 Beaufort Street (Management) Company Ltd., 114 Beaufort Street, L

Dear Conrad, Waterproof multiway is difficult. I like Teuchels, Nowadays Amphenol Tuchel, eg C016 10D006 000 12 Regards, Alwyn _____________________________________________________ Alwyn Seeds, Direct

Dear All, Have used both mains to mast-head and 110V also. I agree that using sense wires is very risky in a high RF environment. For mains to the mast-head, make sure all the metal is bonded and eart

Dear Chris, Yes, Indeed. I recall looking at the very item at the back of Bell Labs., Crawford Hill many years ago. I trust it is in a museum by now. The tale of how they made sure that every other po