[TenTec] MY_BUTTERNUT_HF2V_&_ORION_&_RFI

Wed Jun 29 23:03:17 EDT 2005

A couple of points to add to George's dialogue.

Regardless of the vertical physical height the electrical length of the 
radials should be near 1/4 wave on the lowest frequency used.  A combination 
of equal number of 1/4 wave radials and 1/2 wave radials has been found to 
work even better.  After all, the vertical presents an electrical length not 
just a physical length.  I recall the 75 ohm matching section applied mostly 
to 20 meters.  Also someone commented that the capacitors on the Butternut 
were ceramic and had a history of problems.  The only thing I'm aware of is 
that they didn't like the salt air when we lived in South Florida.  Mine was 
mounted on the dock bollard  with the base some 2 ft over a tidal salt water 
canal.

Having had both a HF6V and a 1/2 wave center fed wire some years ago.  When 
operating HF packet I devised an electronic automatic method to switch 
between the two antennas based on the TU request to repeat packets.  This 
method counted the request and after the 3rd request would switch antennas 
during the receive period.  In just about every case one antenna would 
provide better through-put than the other one.  Frequently during conditions 
of fading the system would switch 10 to 20 times in a 2 or 3 minute period. 
The result was very high accurate data through-put with very few errors and 
thus very few extended request for repeated packets.  General observations 
indicated that when signals were down on one antenna they were up on the 
other one.  Again, this condition could and would change in a matter of a 
few seconds thus the necessitation or need to switch antennas.

George, I do hope you have those driven grounds bonded to the AC mains 
ground and all other driven grounds around the property.  Failure to do so 
will produce a step voltage between two different ground during a near-by 
lightning strike.  Equipment connected between the two different grounds 
will then share the current flowing between the two different grounds.  The 
result is that one can observe extensive equipment damage or worse.

As to the value of internal tuners, well that's the reason I use only 
external tuners.  I figure the best application for the internal tuner is to 
adequately match the input Z of the legal limit amp (which is always 2:1 or 
better) and thus improve the overall IMD of the station.

73
Bob, K4TAX

----- Original Message ----- 
From: "George K" <w2yj at highstream.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Wednesday, June 29, 2005 8:47 AM
Subject: [TenTec] MY_BUTTERNUT_HF2V_&_ORION_&_RFI

> Just put up a Butternut HF2V vertical (80-40-30 meters) with the 30 meter
> add on kit. I buried 19 radials each 70 feet long 1 inch under the ground.
> Why 19? I got board. Why 70 feet? Seemed a good length although they only
> had to be the length of the vertical, 32 feet.
> The vertical seems to be working great so far. I haven't had a chance to
> compare transmit to my 270 foot center fed with 450 ohm ladder line
> terminating to a balun yet. The 270 footer is up at 50 feet.
> The vertical is only 1/2 S unit or so below the 270 foot center fed on
> receive, and sometimes is better.
> I have an 8 foot ground rod at the base of the vertical and a DX 
> Engineering
> radial plate that made the radial connections easy.
> This HF2V also has a 75 ohm matching section because of the added 30 meter
> kit.
>
> As for RFI and the Orion. I also had to re-invent my shack setup such as
> moving the 450 ladder line outside the house and establishing a good earth
> ground that is 2, 8 foot ground rods outside the 1st floor shack window 
> that
> terminates on a single point ground connection in the shack. Water pipe
> didn't cut it!
> I also found that running the SSB menu "TX AUDIO SOURCE" on BOTH when
> running SSB high power screwed up my audio, big time. Setting it to "MIC"
> cured that. I run PSK31 using the AUX input and when set at BOTH the Orion
> didn't like what was coming in the AUX input when on SSB.
> By the way, the Orion is working great!!! Good to know that it is up with
> the best receivers made.
> Just wish it had a larger range internal auto tuner. Maybe Ten Tec will 
> come
> out with a larger range internal tuner or upgrade the existing one?
> All is quiet now!
> George
>
>
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