[TenTec] OT: Question to the group

[rick@dj0ip.de]

FULL AGREEMENT GARY, EVERY WORD.

RECOMMENDATION TO ALL:  if you can find a good JVM, buy it.  You'll never regret it.

WARNING:  More than half of the JVM's I have seen at hamfests were garbage on the inside and not worth much more than the scrap metal value of the box.  BEFORE YOU BUY, remove the 30 or so screws and take a look and the inner components.

Tip:  Most people selling these won't want you to open them.  When I bought my last one, I offered the OM $10 to allow me to open it up.  Said if it is clean, I will buy it and the $10 goes towards the purchase.  If not clean, I won't buy it but he can keep the $10.  If he still won't let you open it, DON'T BUY IT.  It probably has a melted coil form (the larger coil) and is no longer balanced.

73
Rick, DJ0IP



-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Gary J FollettDukes HiFi
Sent: Monday, July 18, 2016 4:13 PM
To: wb5jnc at centurytel.net; Discussion of Ten-Tec Equipment
Cc: Paul Christensen
Subject: Re: [TenTec] OT: Question to the group

Antennas and tuners are fun. They are about the last bastion in which hams can still perform meaningful experiments and produce publishable results. 

Radios have simply gotten complex to the point at which everyday hams can no longer do much with them but plug them in and turn the knobs (or press the keys).

SMD’s and SDR’s only serve to take hams farther from being involved with their radios’s operational theory.

Antennas (and tuners), on the other hand, offer an opportunity for one to perform mathematical modeling to predict designs, optimize them, build them and finally test them.

Paul and Rick both have shown extensive knowledge, both in terms of modeling and practical construction. Their input is very valuable to this discussion.

I do not yet have the time to go into those aspects of antennas and tuners since I am still spending my time doing lab science on chemical sensors and flame detectors.

Therefore, my expressed opinions on the topic are based only upon my own practical experiences, some of those being over 40 years ago.

Thanks for an interesting discussion in which I received more than I gave.

I admit to having overstated the EFJ Matchbox in terms of being the “best ever”, but it is better than most I have seen lately, and t worked in every application in which I tried it. Plus, it never arced on me.

It’s kind of like a restaurant owner saying "Our restaurant has the best burger anywhere”. Really? Have they tried all of them and taken into account that different people have different preferences in burgers?

Gary

W0DVN

PS: Does anyone know why Ten ten chose to allow operation of the internal auto tuner in the Orion only on antenna 1 output? Everybody else seems to have figured out long ago how to do the antenna switching AFTER the tuner so that it would work on both antenna outputs.


PPS: The EFJ Matchbox was a  real pain to repair if the band switch seized up (which it frequently did). The level of disassembly required to remove the shaft from the switch, clean and lubricate it, was far disproportionate compared with other tuners. It is nice to see that Nye Viking carried this tradition forward with the MB5 VI series. What a masterpiece of design in terms of making parts nearly impossible to remove for repair! Add that to the fact that there were several designs for the directional coupler, only one of which was documented, and you have good reason to make parts mules out of some of them.



> On Jul 18, 2016, at 8:38 AM, Al Gulseth <wb5jnc at centurytel.net> wrote:
> 
> Paul,
> 
> Why the need for a rotating turret? Wouldn't switching taps accomplish 
> the same thing? Cliplead taps on the coil have been a staple of link 
> coupled systems since the early days of ham radio, and it seems to me 
> that one could locate the optimum taps for each band and then use relays to switch them.
> Doing it that way shouldn't be any more complex than a typical autotuner is.
> 
> 73, Al
> 
> On Mon July 18 2016 6:47:02 am Paul Christensen wrote:
>> ...
>> A remote-controlled link tuner would by my Holy Grail, but the 
>> mechanical complexities start getting in the way of improved 
>> efficiency.  To do it right would require separate link coils moved on a rotating turret.
>> ...
>> 
>> Paul, W9AC
>> 
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec

_______________________________________________
TenTec mailing list
TenTec at contesting.com
http://lists.contesting.com/mailman/listinfo/tentec