With short length's of coax, [no more than aprx 3'], the input swr between either my FT-1000-D or my FT-1000-MK-V... and the input to my Drake L4B is dead flat. Once the coax is lengthened to aprx 6'
Well, if there is SWR on the line, then it is an impedence transformer and the amount of transformation is determined by line length. SWR is, by definition, the same everywhere along a length of loss
Jim, Have you tried a different SWR meter? It could be that the directivity of your meter is poor and as you add coax, the voltage maxima changes position on the coax allowing a small amout of input
It seems the same misconception has appeared on two reflectors simultaneously, the TT reflector and this one! That being that adding a length of transmission line somehow affects the SWR on the line.
The in band match may well be just fine, but any harmonic energy will be mismatched by the tuned input stage and will be reflected, upsetting the impedance seen by the rigs LPF at that harmonic in a
The hb amp resides in the Hmm. Next door, does this imply a different power circuit? Possible a ground loop problem? Steve _______________________________________________ Amps mailing list Amps@conte
This is a common phenomena and many amp users see it with a variety of amp makes and models. Alpha recommends 3 feet, and that works great. There must be another magic length longer than 3 feet, but
Hi Jim, What you may be seeing is the short transmission line is not really acting as a transmission line. When a transmission line is short (in wavelength) the load dominates the impedance rather th
Could it be the tuned input circuit in the amp you are driving just does not have enough range to bring it into a perfect match with your driver? The mismatch may be more noticeable the longer the le
True as long as the characteristic Z of the additional line remains constant. In the literature, this footnote needs to be added to the general statement above. It's been repeated over-and-over agai
Collins wants 20.5 feet of RG58 to their 30L1. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
No! The 30S-1 recommends a length of 20.5 feet but the specification for the 30L-1 was changed to basically any length of cable with 48 inches being the generally accepted length of RG58/U because th
YES... or what my 30L1 books says... 5th Edition, 1962. Got a later book or service bulletin that shows the change? No! The 30S-1 recommends a length of 20.5 feet but the specification for the 30L-1
There was a later Service Letter, not a true Service Bulletin put out rescinding this requirement. Somewhere, I think I have a copy of the Service Letter. I will try to find it. I don't know if ther
Mine is a late RE. Can't get behind the desk, at the moment, to check SN. I've used any length on hand with no issue. Maybe they did something to the tuned input or the manual writer just grabbed the
I ran a 30S1 for years with random lengths of coax between the amp and exciter. It never was a problem. 73, Joe K2XX _______________________________________________ Amps mailing list Amps@contesting.