10m Manpack is finished

After a bit of work the 10m manpack is finished. It's built on a Philips TP-92 portable chassis (originally for the Philips FM92 radio) and one of the benefits is that any compact/mobile radio can be added to the unit. I've currently got the Dragon SS485H in there but with a bit of rework my Alinco DX-70 could be used instead.

 

The radio is attached by removing the top cover and riveting it to the TP-92 door. I could have gone with a normal mounting bracket but wanted to maintain the lowest profile for the unit. This makes it a pain to open up the unit as the radio has to be unscrewed from it's top plate but not the end of the world.

 

 

I'm running a 5AH LiPo battery from Turnigy which replaces the original SLA batteries. The original charging circuit and speaker have also been removed. I've added a Power-Meter to monitor the battery......but have put it after the regulator so won't get too much useful info although the ammeter measuring instant and peak current is a good tool to have. With the LiPo in place and the potential to dump a lot of current quickly I have gone fuse crazy with 2 internal fuses and one chassis fuse on the outside.

 

Without the original internals it does lose some of it's weight and potentially some of it's stability although I have not seen this as being an issue so far. Current weight without an antenna is 4.4Kgs.The main antenna is the 2.7 metre ANT-129 military antenna I got in from Greece - great buy and recommended. Without a tuner I am still getting a sub 1.7 SWR on 10m. If you are looking for one for yourself I bought mine on eBay from a great seller (and their eBay photo below):

Military-Whip-Antenna-ANT129-22-30Mhz-New-Old-Stock-PRC-Army-Radio-Singcar-radio

 

I'm not running any counterpoise at the moment as when I tried 2 3m wires my receive went backwards so that area needs a little bit of work.

 

I'm thinking it's nearly time to join the SOTA ranks and start hiking........

VX-7R can hear again

RF Repairs got back to my email with a lead time of 6 weeks for the part to be in the country. I spoke with the guys at JNB Electronics (http://www.jnb.com.au/) who had the part on hand, shipped next day and in my letterbox the day after. Great service. After a stiff drink I opened up the handheld, following TimC's instructions (http://pages.cs.wisc.edu/~timc/e/vx7r.html) I was able to easily replace the part and then put the unit back together...twice - I forgot the battery latch. Whack on an antenna and hearing was restored. Always great to make your own repair and I'm glad it was through hole as I'm not an SMD guy.

Yaesu VX-7R has gone deaf

I turned on my Yaesu VX-7R after a long time of inactivity and found it to be a little deaf. By comparison my Alinco DJ-G5 was a powerhouse of sensitivity. Swapped antenna, completed a factory reset...no difference. It's out of warranty so no chance of getting it repaired from the original buyer - Andrews Communications. Time to google it and I found that there is a problem with one of the ceramic crystals in the radio that fails and leads to no sensitivity on NFM receive.

http://pages.cs.wisc.edu/~timc/e/vx7r.html

I've hardly used this unit so I'm not very pleased that it has broken while sitting in a drawer. Anyway, I emailed RF Repairs (http://www.rfrepairs.com.au/) and will see if they have the part on hand and if I can get it going again.

When masts are not as they should be...

Myself and Dan went to pick up the 10m mast and found it was not one continuous mast, not even 2 pieces, but about 5 seperate sections bodgied together - even had a tyre iron in there to complete the friction coupling. I got a lot of RG213 co-ax, the UHF CB 6DB and 9 DB antennas, the sections of mast and that was it. The antennas have seen better days but I have restored one of them to a working condition which will probably go up on the new mast. Speaking of which I will still need to buy a new mast but can use the sections I got on the weekend as a cross beam.

No new contacts to report but I have made some progress on the 10 metre man-pack/portable. I purchased a Philps TP-92 which was used to set a Philips FM-92 up as a portable unit. I've now put my Dragon on there and started re-fitting a lot of the old and obsolete components. The watt meter has arrived and I'm waiting on the Li-Po battery and regulator to arrive before I commence the wiring.

Reached the DXpedition on Banaba Island (T33A)

Pleasantly surprised to make it into Banaba Island tonight. There was a pileup on 40m with a lot of activity on and around the split frequencies with the added bonus of some deliberate interferenceas - everyone tried to get T33A into the log. I had no joy getting through the pileup but just as I was to call it a night the op changed their listening frequency and I was first on the new one and picked up the contact. The new Alinco can at least make it the 4 thousand kilometers to Kiribati in the central Pacific.

www.t33a.com

Some changes to the station and a quick update.

Latest addition to the station is a new (to me) Alinco DX-70 which has just arrived from the states.

In great condition although I have not had many contacts on it as yet so still no decision on performance. I am 50:50 on whether I prefer the receive on the Kenwood TS-120V.....

To coincide with this my main 10M vertical threw a wobbly and jumped to a SWR of over 10:1 across the board.

I assumed this was the feed line and dropped the antenna for a quick look....not the feedline. Tried to retune, no go. Took a while to notice that the antenna was shorter than usual. One of the screws holding two sections together had sheared and the antenna had telescoped by one section. New screw, retuned and away we go. Well almost. I don't have the same magical tuning with great resonance on 7Mhz and 28Mhz. Such is life.

The EFHWV (http://earchi.org/proj_homebrew.html) is up and running and it is a cool antenna. All set up for portable operation as a sloper with my 7 metre squid pole. I'm thinking of running one of these at the shack as a permanent if I can work out how to string it up with the vertical height I have. Speaking of portable I have dismantled my Dragon SS485H manpack.

I'm looking to rebuild something a little smaller and more self contained. Lighter more efficient batteries are on the cards as well as SLA batteries are just too heavy. Get this one sorted and some SOTA activations could take place.

I'm also picking up a 10 metre mast on Saturday and chopping it down to be a 6-7 metre mast with 3 metre boom. 1 pole = more antennas on it. I'm not decided on what to put up there yet but the UHF CB dipole I'm running is giving me poor performance so a vertical may be the go....luckily the pole comes with a 6DB and a 9DB vertical, only snag is I have to dismantle it as well.....still, the price is right. Gold Coast Amateur Radio Society (http://www.gcars.com.au/)had their annual hamfest yesterday and despite my best intentions I couldn't make it. Have to be next year.

VK4RADIO now has a facebook page

I've added a VK4RADIO page to Facebook. This is just to cross-post the posts from the blog over to Faceplant I'll also add in some ham radio pages and links from facebook to go with it.

https://www.facebook.com/vk4radio