Reminder:
Wednesday Evening 40 and 80 meter Nets

When:
Wednesday, 27 March 2019
8:00pm to 9:00pm
(GMT-05:00) America/Chicago

Where:
40 and 80 Meters

Organizer:
jomatlock@...

Description:
The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS will be Bill KV6Z.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.

View Event

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Anyone have a 2 meter transverter  (TV 502S ) or a VFO-520S for sale reasonable? Please contact me at sparkyvaughn2@... or 580 583-7076. Thank you. 72/73

Reminder:
Wednesday Evening 40 and 80 meter Nets

When:
Wednesday, 27 March 2019
8:00pm to 9:00pm
(GMT-05:00) America/Chicago

Where:
40 and 80 Meters

Organizer:
jomatlock@...

Description:
The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS will be Bill KV6Z.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.

View Event

This is the dummy load antenna that I built and use:

I am listening on 40M CW with receiver built from VK3YE circuit Dec 2017. It uses 2 transistors, a 386 audio chip, 716 resonator, three diodes for the "varactor", three potentiometers,  and a home etched circuit board.  After finally putting it into a box, have been listening with it.  For something so simple, ( and cheap ) the performance is amazing, stable and sensitive.  Tunes 7.028-7.070.  Started here http://home.alphalink.com.au/~parkerp/projects/projresrx.htm

Curt KB5JO

Dave -

I would also like to make the mods you list. In addition, I would also like to have another pushbutton switch. I will gladly pay you for all parts, including shipping.

Tnx, Paul, AI4EE

Folks-

Here are several easy mods to improve Hilltopper performance. They address audio levels and quality.

1)   'Loud sidetone':

The value of R8  (now 22k) can be increased to 47K to 100K.  (This change has been posted before, but it's worth including in this summary )

2) 'Low audio'  

The values of R5 (150K) and C22 (470 pF) may be changed to 330K and 220 pF respectively.  This yields a gain increase of 6 dB without affecting that stage's rolloff characteristic.

These two components are in 'tight quarters'- between U3 and the pushbutton switch.  Cutting one or both component leads and tacking the new components on the underside of the board makes the change much easier. 

 But wait- there's more!......

As some of you have noted, there's a 'screech' on loud CW signals- it necessitates riding the gain control. I evaluated samples of a more robust op-amp-  the NJM4556AD.

3) Replacing the NE5532P with that new device eliminates the screech. You'll hear some distortion when limiting occurs, but it's much less objectionable than the NE5532's rude noises. Its 'limiting' threshold is also about 6 dB higher than the present device.  The net result of this change, combined with 2) above,  is 6 dB more audio without the rudities (that's a word!).

Note that if you increase the gain without replacing the IC, you'll find yourself riding the gain control more often

------------------------------------------------

Here's the deal:

If you'd like parts for fixes 1) and 2), simply send me your address and I'll drop them in the mail to you.

I can provide the NJM4556AD as well, but I'd need to charge for it at my cost.  Most of that is postage- nearly $4 for a 'non-flat' mailing these days.   This part is also readily available through Digikey and Mouser.

73- Dave Benson, K1SWL

email: davek1swl at gmail.com

About two years back I made an OzarkCon QSO Party dummy load out of NiChrome wire. Measured off enough to have a DC resistance of 50 ohms, which was about 50 inches for some fine gauge stuff I had here. It formed into a loop about 17" in diameter, using some polyethylene tubing to define the shape. Since the RF resistance would be somewhat higher I re-measured the formed loop with an antenna analyzer and trimmed for close to 50 ohms resistive part at 7 MHz. The loop, of course, has some inductance, and it took about 200 pF in parallel to tune out that reactance.

Some small PVC pipe and fittings to make a suitable stand and it was ready to QSO. Alas, I had so much fun chatting and visiting that I didn't put it on the air for more than a few minutes.

If you don't have any NiChrome you could achieve a similar effect by stringing a few resistors end-to-end in series, maybe with some wire between them to space them out enough for a loop a foot or so in diameter.

Jim, N5IB

PS... also check out in this group's Files section "Quick HF DF Loop.pdf " uploaded Feb 9 of 2017, as an idea for the oscillator hunt.

that isn't a dummy load. . that is a full fledged antenna. . .
The 50 ohm is used to insure a impedance match to the transmitter.

you can do the same thing with very large loops. . .. measuring the
resistance of the wire per 100 feet, and building an antenna that is
long enough to equate to 50 ohms. . . .

No tuner needed. . .

--------------------------------------------

Easy one!

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Charles,
My dummy load antenna is a dummy load built in a ALTOIDS tin with banana connectors on the OUT end. I attach a hank of wire and string it around the room and it works great with a little more wire to radiate with.
de Paul