f Of Ron Wagner
Sent: Tuesday, March 03, 2009 2:23 PM
To: drakelist@zerobeat.net
Subject: Re: [Drakelist] TR7 with Modern Linear
Folks, this looks like one for something I saw, I think in Ham Radio
magazine, years ago.
There was an article that used the station dummy load as the primary part of
a RF
Folks, this looks like one for something I saw, I think in Ham Radio
magazine, years ago.
There was an article that used the station dummy load as the primary part
of a RF divider to send to the station's tuner. It would provide at worst
something like a 2:1 SWR. Something like a 100 ohm pic
Hi John:
I have a similar problem here but it isnt necessarily limited to new
linears. Depending on the tube and circuit configuration, input drive
requirements can be quite low.
I think the best solution, not necessarily elegant, is to use a pad
between amp and trans. Will require possibl
f Don Cunningham
Sent: Sunday, March 01, 2009 2:03 PM
To: k4...@mindspring.com; drakelist@zerobeat.net
Subject: Re: [Drakelist] TR7 with Modern Linear
Garey, et al,
I tried the "fake ALC" method with my old KWM-380 and an Alpha 91b after
fiddling with ALC on the 91b with little success.
On Sun, 1 Mar 2009 17:18:56 -0600, Don Cunningham wrote:
>Remember one thing, John is in the UK and is limited to 400w out, not full
>power for the Acom!
Yeah, I sort of gathered that is why he was wanting to reduce his drive
power to 20 watts. The 6dB attenuator for tune mode of the amplifier
elist] TR7 with Modern Linear
On Sun, 1 Mar 2009 21:22:12 -, John Stringer wrote:
My Linear is the ACOM
1000 which I believe is similar to the Alpha 91. It has no ALC connection.
In looking at the A1000 manual online, it is a grid driven tetrode with
a swamping resistor in the grid circ
I run a TR7A into an Ameritron ALS-600 amp and on more than on
occasion I have wiped out the FETs because of the leading edge spike.
I have the alc set to 120 watts on 20 meters and on 75 meters it
still only puts out 120 watts constant carrier. But on ssb with a
peak reading wattmeter
such as m
On Sun, 1 Mar 2009 21:22:12 -, John Stringer wrote:
>My Linear is the ACOM
>1000 which I believe is similar to the Alpha 91. It has no ALC connection.
In looking at the A1000 manual online, it is a grid driven tetrode with
a swamping resistor in the grid circuit. Which sounds very similar to
On Sun, 01 Mar 2009 14:35:30 -0500, Garey Barrell wrote:
>There was a blurb about a "keying" spike when the TR-7 was
>first powered on in the early units, but I didn't think it applied to CW
>or SSB operation.
The power on spike, I think, was related to the VOX circuit. It is
fixable with a mod
connection.
John. GI3KDR
-Original Message-
From: drakelist-boun...@zerobeat.net
[mailto:drakelist-boun...@zerobeat.net]on Behalf Of Don Cunningham
Sent: 01 March 2009 19:46
To: k4...@mindspring.com; drakelist@zerobeat.net
Subject: Re: [Drakelist] TR7 with Modern Linear
Thanks for the thoug
PM
Subject: Re: [Drakelist] TR7 with Modern Linear
Don -
Dunno, never tried it on a TR-7. Doesn't seem like there should be a
problem, since the "fake" ALC voltage is present before the transceiver
is keyed. There was a blurb about a "keying" spike when the TR-7 was
fi
dge spike", althought the amp would take
it, 150w into this amp will give you 2k into a dummy load, hi.
73 and thanks for your input Garey,
Don, WB5HAK
- Original Message - From: "Garey Barrell"
To:
Sent: Sunday, March 01, 2009 12:12 PM
Subject: Re: [Drakelist] TR7 with Mo
riginal Message -
From: "Garey Barrell"
To:
Sent: Sunday, March 01, 2009 12:12 PM
Subject: Re: [Drakelist] TR7 with Modern Linear
Jim -
Some good points there. However, most are related to the "dynamic"
action of ALC, NOT a fixed gain adjustment as I described. I and
On Sun, 01 Mar 2009 13:12:04 -0500, Garey Barrell wrote:
>Some good points there. However, most are related to the "dynamic"
>action of ALC, NOT a fixed gain adjustment as I described.
I remember now, from Sept. 2008:
http://www.mail-archive.com/drakelist@zerobeat.net/msg10036.html
We think a
On Sun, 01 Mar 2009 13:12:04 -0500, Garey Barrell wrote:
>Some good points there. However, most are related to the "dynamic"
>action of ALC, NOT a fixed gain adjustment as I described. I and
>others have used this technique with success for a long time, but there
>is always new information!
Jim -
Some good points there. However, most are related to the "dynamic"
action of ALC, NOT a fixed gain adjustment as I described. I and
others have used this technique with success for a long time, but there
is always new information!
Of course there's always the argument that says "all
On Sun, 1 Mar 2009 09:26:20 -, John Stringer wrote:
>The linear requires only 20watts drive for 400 watts out (our limit).
>In SSB the only output control on the TR7 is the Mic Gain.It is a real
>fiddle to adjust this for 20 watts and more so to keep it there. The
>smallest touch on the gain c
I am using my TR7 with a modern linear and have come up with what can best
be described as an irritation rather than a problem.
The linear requires only 20watts drive for 400 watts out (our limit).
In SSB the only output control on the TR7 is the Mic Gain.It is a real
fiddle to adjust this for 20 w
l
Sent: 30 September 2008 22:06
To: Drakelist
Subject: Re: [Drakelist] TR7 with modern linear
John -
There are a few ways to do this. I'm not familiar with the Acom unit,
but apparently it doesn't require much drive.
1. Construct a "power pad" to put between the TR-7A and t
I run a pad between a modern transceiver and a transverter. There are
two issues with this approach when applied to a Linear.
1) The excess drive power you have to dissipate as heat is
considerable so you have to plan for it.
2) The loss of the pad adds directly to the receiver noise figure
unless
John -
There are a few ways to do this. I'm not familiar with the Acom unit,
but apparently it doesn't require much drive.
1. Construct a "power pad" to put between the TR-7A and the amp input.
This is probably the "best" way from a distortion standpoint, but
inconvenient unless you use t
Way back in the 80's I used a TR7 with an L7 which ,of course, had ALC.
Everything worked well together.
Now, about 27 years later I have bought a nice TR7A and am trying to use it
with my modern Acom 1000 linear which has no ALC provision.
There is one problem as a result. I have to turn the drive
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