That is very odd. ..? I have owned several LK amps.? They will cover the entire band in the No tune.? The SWR needs to be fairly low however, Most people do not have an antenna that covers the entire band anyways.
Some models have a switch for 160 and 80 to cover the entire band.? Its two presets per on those bands.??
Also, my Alpha 374A works the same way. It also covers the entire band.
I think the reason why some people don't like them is?because they feel they are missing something by not tuning up to max power each time.
Who the hell wants to retune a damn amp 20 times an hour moving around from band to band and from low to high on the bands.? Nobody.? It ruins the fun of working DX.
These things are really nice and have a huge convenience factor. At the expense of some peak power output.?
Another huge advantage is some OPS, NO MATTER WHAT, will never tune the amp correctly.? They will mistune it, Burn it down, over and over and over. NT amps remove all of that.? The OM can just key down and operate with little risk of blowing the amp up.
For 1kw or so this kind of amp is really nice and fun to use.
C
All the LK series NT ( no tune) amps have several small load and tune capacitors. You must pre select the frequencies you want to operate on each band first.? Then you use the internal load and tune caps to load the amp up for those frequencies per band.
?Once you pre load the amp on the various bands you will only get a marginal excursion from the?selected frequency to an off frequency away from that.? You will never get?coverage of the bottom and top of the band.? As far as I¡¯m concerned these amps are only
good for ops that ONLY frequent certain frequencies on each band, like net control operators.? Anyone wanting the freedom of the whole band with full power output would never want these amps.
The loading process is pretty tedious because it has so be done with a long flat blade screwdriver and I think it needs to be done in a certain order but that¡¯s I¡¯m not sure of.
On Monday, March 25, 2024, 12:58 PM, Bob <W4JFABob@...> wrote:
Hi all,
Tomorrow I'm going to see a friend?that has some kind of problem with his LK-450 NT amp.
At this time I have no idea what the problem is due to inconsistent?information.
But I have a question, I've never worked on one of these but I'm assuming the network is
very broad banded and you only adjust a "fine tune" for your operating frequency.
My common sense tells me that inside there must be some kind of "broader" (lack of a better term) adjustment inside to get the network in the ballpark so a fine tune can dial it in.
I'm thinking that especially on 160 and 80/75 it would be critical to get it close for either the top of the bands or the bottom of the bands.
Am I on the right track? Also, is there any known common problems I should?be aware of?
Thanks all. Bob? W4JFA
Bob