ATV: 70 cm Linear Amp
Downeast Microwave has finally done it and came up with a 70cm linear amp. They sent me a prototype
to test out on ATV and it works great with no modifications. My review will appear in the Summer issue
of Amateur Television Quarterly which should reach subscribers in early August. Basically I used one of
our TC70-20Sa ATV transceivers and varied the drive and pedestal set up. The new Downeast
Microwave 70225PA with 10 Watts pep (sync tip) got 218 W pep out with just a little sync stretching. No
sync stretching was necessary up to 150 Watts out it is so linear. In fact the new Videolynx VM-70X
4 Watt rated transmitter (see that review in the next ATVQ also) got 156 Watts out with 5.1 pep drive and
just slight sync squashing. So any ATV transmitter up to 5 watts pep can drive this amp with no adjustment
or set up necessary. The older our older PC Electronics 10 watt or newer 20 Watt transmitters or
transceivers just need to do the set up procedure by first turning down the output pot to below 10W.
Availability is estimated about October. I’ m starting a list for those that want to get one of the ATV
configured units (fans, T/R relays, vswr and over temp protection) as soon as they are out. I will stock
them initially, but DEMI's usual time quote is 6-8 weeks. Price will be around $500. I will notify those on
the list when I get stock on a first come first served basis and you can opt in or out a that time. Power
requirement is 28V at up to 12A and Downeast is working on a companion power supply.
Tom O'Hara W6ORG P. C. Electronics 626-447-4565 m-f 8am-5:30pm m-th
www.hamtv.com
ATV: Review of 70 cm Linear Amp
From: TOMSMB@aol.com
In case you don't get ATVQ (but how could that be?) and therefore did not see my review of the Downeast Microwave
70225PA 225 Watt 70cm linear amp and the new Videolynx VM-70X 4W ATV transmitter
in the Summer 2005 issue on pages 36 and 37, you can now download the reviews by
going to the "New for 2005" page on my web site:
http://www.hamtv.com/newstuff.html and clicking on
the respective photos. Tom O'Hara W6ORG P. C. Electronics www.hamtv.com
ATV Crystals
From: TOMSMB@aol.com
I have a variety of crystals left over from before we switched over to synthesizers which are available for
$5 each. You can see the list and product they were used on by going to our web site, click on Specials
and Surplus, scroll down to Parts, then click on Crystals. Or go directly:
http://www.hamtv.com/xtals.html
We also have a New for 2005 web page which has some info and pix of the new Downeast 225 Watt 70cm
amp and the Videolynx 4 Watt 70cm transmitter in case you cant wait for my review in the next ATVQ.
Tom O'Hara W6ORG P. C. Electronics www.hamtv.com
626-447-4565 m-th 8am-5:30pm Pacific time
Changes announced for ARRL International EME Competition
The ARRL Program and Services Committee has approved the addition of a Single Operator Assisted
(SOA) category for single-band and multiband ARRL International EME Competition entries. Under SOA,
one person performs all operating and logging as well as equipment and antenna adjustment and
alignment. The use of spotting assistance or nets (operating arrangements involving other individuals,
DX-alerting nets, packet, etc) is permitted. The new category will be in play for the upcoming 2005 contest
season, although it was not approved in time to make the contest announcement in August QST. This
change means that single-op single-band and multiband EME event participants now may compete as
unassisted or assisted. Certificates will be awarded for the new category. The EME competition cover
three 48-hour weekend periods (0000 UTC Saturday through 2359 UTC Sunday). Dates and designated
bands for 2005 are September 24-25: 2304 MHz and Up, and October 22-23 and November 12-13: 50 MHz
through 1296 MHz. For more information contact ARRL Contest Branch Manager Dan Henderson, N1ND.
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12
BRATS Home Page
