Excited


Marv K2VHW and I, under the auspices of the South Plainfield Amateur Radio Club, will be teaching a course for those in the greater Central New Jersey area who want to earn a Technician class license.

Here's the flier that Marv designed to advertise the class:


I'm excited, because so far we have eight potential students who have pre-registered. We have room for more, so if you're interested or know someone in the Central NJ area who might be interested, contact either Marv or myself.  We would also ask that anyone who has pre-registered or wants to register, to please try to attend the next SPARC meeting on Wednesday, September 17th at 7:00 PM at the South Plainfield OEM building.  At that time, we will be taking count and placing a group order for license manuals for the class.  Marv and I are both ARRL Registered Instructors, and a such we can apply for a group rate for the manuals.

72 de Larry W2LJ
QRP - When you care to send the very least!

Larry Makoski, W2LJ, is a regular contributor to AmateurRadio.com and writes from New Jersey, USA. Contact him at [email protected].

Cycle 24 Battles On

Courtesy: http://www.nasa.gov
It seems there are still a few surprises left in the strange life of Cycle 24. Yesterday's major X1.6 solar flare seems to be nicely positioned for an earth-impact on Friday. The blast follows an earlier M4.5 flare the day before and the one-two combination could deliver some interesting VHF propagation as the solar stream impacts our planet.

Courtesy: http://www.nasa.gov

Video of the event shows what looks like a near full-on earth-directed hit but for a northerly component. Only time will tell.




Sky watchers as well as VHFers should be alert for possibly major auroral displays on Friday or Saturday.

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

A New 630m Loading Coil & Variometer



I've decided, for the time being, to keep my 2200m (136kHz) antenna tuning system separate from the 630m system. This means that I'll need to build a new loading coil, variometer and impedance matching transformer. I'm not really sure why I should maintain the 2200m capability since there is not really much activity here. The only two excuses that I have at present are the fact that it took a heck of a lot of work to get to this point (but it was mostly "fun work") and that the U.S. may be getting the band soon. I'm also not convinced that even if the U.S. does get the band that it would translate into much new activity....so, for the time being, I will keep the system intact.

I've used an online coil calculator to design the coils needed for loading and for the variometer....it will be interesting to see how close the finished values compare with the calculated values. I hope they're not too far off! Here is what the plan calls for:



The main loading coil will be built on a low-loss 6" styrene pipe coupler using #16 solid copper transformer wire, spaced at 3mm. The coil will be elevated above the main form by strips of styrene rod that I have filed small notches into, every 3mm. The rod height will be staggered around the form, gradually stepping down one full turn every 360 degrees. Inside the main coil, the smaller variometer coil will be wound with poly-covered #18 stranded wire on a short length 3 1/2" PVC pipe.




Hopefully I'll get something that tunes from 130-230uH, approximately....if so, I'll not only be happy, but really surprised!


Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

9/11 – Never forget.





72 de Larry W2LJ
QRP - When you care to send the very least!

Larry Makoski, W2LJ, is a regular contributor to AmateurRadio.com and writes from New Jersey, USA. Contact him at [email protected].

MFJ 1788 and humid weather

Large plate capacitor
Over the past few weeks I have been very busy with work and not really anytime for radio or anything else really. I was on the radio for a very short time last week and the weather outside was very humid and HOT! The antenna I have is the MFJ 1788 loop and I have always been able to get a decent SWR on most bands the antenna was designed for. But for some reason I was not able to get an SWR under 2.1:1 on some bands the best I could do was 3.1:1. It turns out that the Humidity can affect the MFJ 1788 antenna and my guess is since the antenna has a large moving plate capacitor the humid air affects the air gap between the plates? The other day the weather was back to cooler non humid conditions and I tried the antenna again and the great SWR was back again. The antenna had not moved and nothing had changed other than the weather.

Mike Weir, VE3WDM, is a regular contributor to AmateurRadio.com and writes from Ontario, Canada. Contact him at [email protected].

FEMA Director Craig Fugate, KK4INZ to Emergency Managers: “What’s your backup?”

FEMA Director Craig Fugate, KK4INZ, debunks the argument that Amateur Radio is no longer relevant in our hyper-connected smartphone, tablet, satellite phone, networked radio system world:

“If you really want to short-circuit your local or state emergency manager who says that Amateur Radio isn’t really viable anymore… ask them this,” said Fugate. “Can you communicate across your jurisdiction or across your state without touching the public switched network?”


Matt, W1MST, is the editor of AmateurRadio.com.

Echolink Node?

Over here in G (or M or 2) land echolink nodes need to have permissions from the grown ups. So I’ve sought permission from Ofcom, with the help of the RSGB. I applied for an MB7 node, which means it is can be unattended. In order to do this I needed a minimum of 4 people who are key holders so the node can be shut down quickly. Sounds reasonable? Sounds a bit British to me. Belt and braces and some more belts just for luck.

The node will hopefully be on 2m and I have been told that if it gets granted then I could expect around 2w ERP. I don’t want to sound selfish but I have only heard 2m simplex used in this area for the local net and once in a blue moon Dent gets activated by a SOTA or WOTA chap(ess). VHF in general is scarcely used and its a shame.  UKAC evenings and the normally quiet repeaters with their occasional skeds excepting mean that both 2m and 70cms are dead.

What can be done about it?

Making it appealing to use, perhaps? A bit of activity always helps.

Internet link may give some users an opportunity not only with existing amateurs but could make it appealing to those on the periphery of the hobby. Makers for example.

Anyway, let the waiting begin and we’ll see where we get to with Ofcom


Alex Hill, G7KSE, is a regular contributor to AmateurRadio.com and writes from Cumbria, UK. Contact him at [email protected].

AmateurLogic 70: Arduino Antenna Switcher

Episode 70 is On-The-Air ...

AmateurLogic.TV Episode 70 is now available for download.

George builds a remote control antenna disconnect switch with an Arduino and a Servo. Tommy experiments with the MFJ Ultrasonic Noise Locator. Peter participates in the 2014 DATV QSO Party.

Details on our 9th Anniversary Sweepstakes giveaway of the Ultimate Mobile Station.

Upcoming personal appearance, events and more…

1:20:13 of ALTV Enjoyment.

Download
YouTube


George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

Win 500 Full-Color QSL Cards

AmateurRadio.com is offering a free prize drawing!

With the help of our generous sponsor, KB3IFH QSL Cards,
we’re holding a giveaway for 500 free full-color photo QSL cards.
This is a US$75 value and open to all licensed hams worldwide!

Read the rest of this post


Matt, W1MST, is the editor of AmateurRadio.com.

Repairing a Kenwood TR9500, Part2 – TX working, SSB RX not

As I suspected the microphone amplifier Q1 in the Kenwood/Trio TR9500 was indeed faulty. The replacement arrived next day and within an hour I had successfully soldered in the new 2SC2240 transistor and it now had audio on transmit.

Transmitting into a dummy load and monitoring on my FT857-D the FM transmission was fine, the SSB was okay, perhaps slightly over driven. I suspected that maybe the previous owner might have twiddled something to compensate for a failing Q1.


In the adjustments section of the service manual VR6 on the IF unit controls the SSB MIC gain. To check the settings it was a case of setting the transmitter to 432MHz and putting an audio frequency signals of 1.5kHz of amplitude 1mV and 10mV from my signal generator on to the microphone terminal, and observing the RF power output, which were the 5W and just over 10W as required. As this didn't need altering I left it alone and boxed it back up and returned it to the happy owner.

Last night was the RSGB 432MHz UKAC Contest and I was hoping to here it on the air, sadly I didn't. It now transpires that there maybe another issue with it, something I should have spotted.

I do remember something strange when doing the initial testing. Connected to a dummy load and in SSB mode the S-meter showed S9+ when in receive but with no audio, turning the RF gain control the meter dropped to S0 and normal white noise static could be heard. It received a SSB transmission from the FT857-D with no issue so I thought no more of it. Being over eager and not experienced with using different rigs I had mistakenly dismissed it and should really have read the operating manual more extensively.

The anomalous S9+ meter reading and no audio occured when the RF gain control was set to the maximum which is the normal recommended setting for operating, I'd simply turned the RF gain control to the minimum mitigating the issue.

Obviously the rigs owner had put the RF gain back to maximum and was now reporting it wasn't switching back to receive. In fact it is but nothing is being heard. Checking the service manual this morning and it appears there is an issue with the AGC circuit (description and block diagram below)


RECEIVER CIRCUIT
.... The signal is picked up from the last stage of the IF amplifier (Q23), then detected and amplified to generate the AGC voltage. The AGC time constant is automatically set according to the mode : FAST for CW; SLOW for SSB. The AGC voltage is applied to IF amplifiers Q21, Q22 and Q23 (3SK73(GR)) and RF amplifier Q51. It is also used to drive the S meter.

It seems the rig may well find itself back on the bench, however this repair could be more problematic!

As I mentioned it was the 432MHz UKAC last night and I had a decent night of search and pounce. Conditions were very strange, lots of fading and strangely some of the usual local operators were not heard. I was very pleased to catch some lift and made a couple of decent DX contacts in Northern Ireland, The Isle of Man, Northumberland as well as Essex and Cambridge.
In a few weekends it is the National Hamfest, which is held in my home town and I hoping to pick up some bargain gear to improve my UHF set up, however from past experience that may prove difficult.

Andrew Garratt, M6GTG, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

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