AmateurRadio.com

The shack has gained a couple of 'new' radios, one of them look familiar?


It is the Trio/Kenwood TR9500 that I repaired last month for a fellow club member. Having no transmit audio I'd replaced a faulty transistor in the microphone pre-amp. Subsequently it's owner reported it was still misbehaving and locking up in transmit mode.

I'd offered to give it another look but the owner decided to cut his losses and wanted shot of it. He had just purchased a nice new radio at the National Hamfest and was also selling a 2m Trio/Kenwood TR9000 multi-mode set to make some room.

I liked the look of these pretty sisters and got both of them for a very reasonable price, the TR9500 costing just £10 in lieu of the previous repair work. I collected them at the weekend and got around to checking them out last night.


The TR9000 is a lovely compact rig, the case has the odd scuff but the front is in good condition and has cleaned up nicely. I just need to attend to the microphone plug as it wearing the ubiquitous piece of brightly coloured insulating tape. It is fully functional and I made a few contacts on it during last nights 144MHz UKAC. It is nice sounding and seems to have a good sensitive receiver.

The troublesome TR9500 has been back on the bench and connected to a dummy load and my X-50 dual-band collinear and I cannot find anything wrong. The ALC 'issue' I suspected was a red-herring, the audio does cuts out and the S-meter goes to S9 but only when the RF gain knob is turned to minimum not maximum as I'd thought, the same thing happens on the TR9000.

It is entirely possible the fault reported by its previous owner is intermittent (a bad joint, sticky relay etc) It is also a possibility that RF was leaking back in the rig causing it to lock up. I plan to use it in anger maybe during next weeks 432MHz UKAC especially if the receiver proves as sensitive as that in the TR9000. 

As I mentioned the National Hamfest took place recently and since it is local to me I decided to go along on both days. The Friday was by far the busier day with lots of sellers in the outdoor flea-market with a genuine 'buzz' which seemed lacking on the Saturday, there were a lot less sellers outdoors.

The main hall left me a bit underwhelmed, the layout seemed a bit messy and some areas were cramped while others seemed to have acres of spare room. It was also very hot in the main hall especially on the busy Friday, however it was still an enjoyable couple of days and met up with some fellow tweeters and operators. 

My purchases were modest and as well as the usual connectors and cabling I picked up a nice as-new 7A regulated linear power supply, a foot switch, a replacement satellite Quad-LNB, a very sorry looking 70cm linear amplifier and picked up one of those lovely Czech morse-keys for when I brave doing the code!

I also picked up this little 2.4GHz B/W video monitor for a whopping £1 and it works a treat. I have a number of 2.4GHz wireless security cameras (purchased back in 2009) intended for a PC-based PVR CCTV system but the whole PC system proved unreliable so they are sitting idle. This little monitor can receive on the four standand channels and as a bonus runs off 13.8V so ideal for sticking in the car and driving around the local housing estate eavesdropping on other similar cameras - I am joking of course!


The very sorry looking 70cm linear amplifier is a Tokyo Hy-Power HL-60U. I found it hiding away in a box of junk on one stall and after a bit of haggling got it for a fiver! From its appearance I really didn't expect it work, especially since the warranty seal had been broken. I wasn't too bothered about the power amplifier I was far more interested if the built in GaAsFET pre-amplifier still worked.


Getting it on the bench I opened the case, expecting to find it plundered and butchered and was pleasantly surprised to find the insides looked almost pristine. I think the main PA transistor may have been replaced, but while it looks a bit messy the flux resin around its joints looks the same as other areas of the PCB so not sure. It looks slightly different internally to some another photographs I found on line and I have searched the web for a manual and schematic with no joy. Tokyo Hy-Power went bankrupt last year and the website and precious data downloads have all but disappeared.


As it looked intact with nothing missing I connected up the dummy load, power meter and fed the input from one of my Baofeng handhelds. It powered up and was giving 15W out for a measured 3W in with no distortion on the audio, so far so good. However after connecting up the FT-857D and slowly increasing the input power is became apparent that 15W seemed to be about the limit of its output, not the 60W as promised.

Removing the dummy load and putting it on the X-50 antenna I had a listen around for weak stations to checked the operation of receive pre-amp and it worked! Should prove useful for the 70cm contests.
Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

I don’t really have time to do a full write-up, but I made a “quick” trip to American Samoa over the weekend to plan a future scientific instrument installation and managed to get on the air for a few hours.  Here are some snapshots from my phone.

Ethan Miller, K8GU, is a regular contributor to AmateurRadio.com and writes from Maryland, USA. Contact him at [email protected].

See http://www.southgatearc.org/news/2014/october/price_of_70cm_handhelds_falls.htm#.VDP48MnTCSo  .
This is incredible: a 5W handheld for less than £8.

Looking on eBay, just £6.99 ($11) will buy a 70cms unit with charger from Singapore. Tell  me, how can ANYONE make money on these?

Thanks to G1KQH, a link to a review:
http://hamgear.wordpress.com/2012/08/11/review-baofeng-bf-666s-bf-777s-bf-888s-and-look-alikes/

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

“The emphasis is fun. The hope is that it will attract new people to electronic design, measurement and experimentation. Hopefully, this site stimulates interest in QRP homebrew electronics.”

That's how Todd Gale, VE7BPO, described his website. Up until this past weekend, Todd site was one of the Web's premier sources of inspiration, accumulated homebrew knowledge and hands-on experimental wisdom. I was shocked to receive an e-mail from Todd explaining that the site would be taken down because of continued  bandwidth / network struggles with his one and only choice of providers. It truly was sad news for myself and the thousands that regularly visit his site for guidance. However, all is not lost as Todd went on to say:

"....I will convert all the site files into pdf files and stick them on a download site sometime in the future. I may re-emerge with a small-scale site or blog at some point, but don't really know for sure."

Happily, today Todd has informed me that he will indeed begin a new POPCORN QRP  blog in which he hopes to update with his benchwork descriptions that we have all come to enjoy.

I have listed Todd's blog site on My Blog List to the right but you may prefer to set your bookmarks for his site. Don't expect too much until later in the month as he is still working his way up the blogger's learning curve....hopefully we will see him back soon. Best of luck with your new endeavour...and, like the original website, I'm sure it will be great!

Courtesy: VE7BPO

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

See http://www.vlf.it/zevs/zevs.htm .

Quite a few VLF/ELFers attempt to copy the Russian ZEVS transmissions to deeply submerged nuclear subs at around 82Hz, yes, you read right, Hertz. At these frequencies even a few watts ERP penetrate deeply in the sea. The Americans used a similar system called Project Sanguine at around 76Hz , but this has now gone QRT. I think they use green lasers now?

The ZEVS data rate is low and usually there are a couple of transmissions a day. Usually Spectrum Laboratory software is needed for long term stability. Several people have been successful, although I have still to try.

I hope the transmissions are just tests these days!

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

The new 'loop' is not really loop-shaped but is rectangular (10' x 20') and more like a Flag antenna shape. I considered a Flag but really don't need any back-end nulling capability since I'm mainly interested in listening to the east and to the north.


The main boom section is composed of two sections of 1" PVC thick-wall (Schedule 40) pipe joined at the center and reinforced with a 10' section of 2" x 2" Douglas Fir. In addition, the boom has a truss of 1/4" Dacron to take out any end-loading sag. The vertical end sections are 3/4" Schedule 40 PVC pipe, fastened with a T at the boom end. The center mast is made of 2" Schedule 40 ABS pipe with a long section of 1 1/2" ABS nested inside that telescopes upward to anchor the truss ropes and give some additional rigidity to the mast.

Main boom and mast construction

This type of construction would lend itself well to anyone interested in a rotating Flag antenna for the BCB / LF or 160m. The cost are very low, the structure is lightweight and the materials are readily available at most hardware outlets.



Looping E/W

Although the preamp is completely sealed and weatherproofed, I still decided to mount it inside a container. The container also provided a convenient anchor to terminate the loop end wires (PVC-coated #18 stranded) without putting any tension on the soldered terminals.

Although I have not had much time to listen, and conditions are still in 'recovery' mode from earlier disturbances, initial indications are that everything is performing as well, if not better, than expected. It certainly outperforms my 10' active shielded loop by a large margin. I have yet to do any serious S/N comparisons between it and my primary LF receive antenna, a large inverted L, which must be tuned to resonance for the desired listening range. I believe that the very quiet loop / Wellbrook combination will provide an overall S/N improvement.

I have always believed that smaller loops provide deeper and sharper front-to-side nulls so I was pleasantly surprised to measure (using Perseus) null depths from 25-30db, on various groundwave signals....more than expected. Skywave signals also deliver sharp deep nulls in the order of 22 - 25db...again surprising, but I'll take them! A brief listen pointing S-E last evening turned up good signals from 1 kw'ers KYHN (1650kHz) in Fort Smith, Arkansas and KKGM (1630kHz) in Fort Worth, Texas. An early morning listen revealed good audio from JOIK (567) Sapporo, Japan and JOAK (595kHz) in Shobu. Down in the ndb band, little 25-watter 'IP' on 210kHz was an all-time new catch from Mobile, Arizona.

There is still much to learn from this new antenna system but the biggest challenge will be keeping it up all winter. I did lose one of my 10' loops after several years, due to wind when the main (un-reinforced) PVC mast eventually failed from flexing fatigue. I will tie the ends of the new antenna down when the winds get strong to reduce as much mast flexing as possible. I could however, run the risk of violating another long-standing radio tradition..."if your antenna stayed up all winter, it wasn't big enough". I just can't win.

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

Series Seven Episode Twenty of the ICQ Amateur / Ham Radio Podcast has been released. The latest news, Martin (M1MRB & W9ICQ) and Colin (M6BOY) discuss the 2014 JOTA Event and Martin (M1MRB & W9ICQ) reviews a visit to the HMS Belfast Radio Club.

 

• WIA plans a submission on new VK operating conditions
• Beta release of WSJT-X v1.4
• Postage stamp features ham radio satellites
• Brazil proposes 5275 kHz to 5450 kHz allocation
• No Ham Radio 4 metre band for US
• SARL change beacon frequency
• Melbourne man guilty of Radiocommunications Act offences

Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].