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Reviews For: Hamtronics R139

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Review Summary For : Hamtronics R139
Reviews: 4MSRP: 239/199kit
Description:
137Mhz WXsat APT Receiver
Product is not in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0044
KB1JGW Rating: 2005-05-12
Good Wx Satellite Rx Time Owned: 3 to 6 months.
I thought it would be fun to build the kit too.
The R139 kit assembly and tuneup directions were OK, but tuning the receiver would probably be beyond the grasp of a first time kit builder. I don't have a signal generator, so I needed to visit a fellow ham that did. I had to replace a capacitor during the tuneup to get a crucial front end tank circuit to tune correctly. The experience has been worth it, and the weather satellite hobby is a lot of fun. The receiver works good and pulls in excellent APT images even at low angles of elevation.
KQ6EA Rating: 2005-02-21
NOT your Father's Heathkit! Time Owned: 0 to 3 months.
I decided to save a few bucks on this by getting the kit version, instead of the assembled one, as I love building things, and have all the tools and experience needed for even complex kits. Well, if I had it to do over again, I'd get the built one. I agree with the original QST review, which compares it to a magazine construction article, where you gather up the parts yourself, and figure out a lot of the 'instructions' yourself, rather than being a full-on kit. And since I've been building kits (AND magazine construction projects!) since I was 12, over 40 years, I'm not just whining here. To begin with, the PC board, which is double-sided with plated-through holes, and of reasonably good quality, is NOT silk-screened or solder-masked, making for a LOT of extra time spent figuring out what goes where, and double checking against the pictorial, the schematic, and the foil pattern to ensure you're getting the right parts in the right location. Hamtronics' method of "painting" the parts on the board must assume you have quite a bit of familiarity with assembling things from scratch! READ the printed instructions before you start, take all the parts out and group them by value, and then READ the instructions again! Read ALL of the pages they give you, as little tips are scattered throughout them. I also added a coaxial power jack, and two 1/8" phono jacks, to the rear panel so it would interface easier with my existing equipment. A "D" size coaxial jack from radio Shack fits the plug on the included power supply.
Once it was built, I had some minor alignment problems, as the cores in the variable inductors were no where near correct "as shipped". And I agree with the other poster here, that three of the five supplied crystals are useless, since the sats are either already dead, or dying. Once you have it built and aligned, though, it works *very* well! I've used it with both a 137MHz Quadrafilar Helix antenna, and a 137MHz scaled version of K5OE's "Eggbeater-II", with very satisfying results. It's a lot of fun to display pictures of the weather over your QTH in real-time.
The main reason I gave it a "2" is because it's just _not_ up to the standards of a modern kit.
K8ZK Rating: 2004-12-25
Simple but effective Time Owned: 0 to 3 months.
I bought this radio after trying both scanner gear and amateur gear to do APT. The design is simple but effective. I am getting good results with a fairly low antenna in a high RF area.

I bought the wired and tested radio. I think it is worth the extra $40 unless you have a test bench available and are into building kits.

The simple design (no microprocessors) means no birdies (e.g. my Timewave TNC plants a birdie right on one of the two active APT freqs). This radio + WXtoIMG is a great starter system. I am using with a homebrew K5OE eggbeater II.

The only two issues I have with the receiver are the use of a DB 9 for power, audio, etc (sort of strange, but they supply a connector)... and three of the 5 crystals are useless, as the Russian Meteor satellites have been down for some time and none are planned. If Hamtronics would replace these old rocks with freqs for the upcoming NOAA N and MetOP birds (NOAA N and MetOP will transmit APT/LRPT on either 137.9125 MHz or 137.10 MHz) this would position this radio for the future (one plus of the synth radios over xtal).
WA8EBM Rating: 2004-12-04
Exceeds expectations Time Owned: 0 to 3 months.
This is a crystal controlled receiver used for monitoring APT transmissions from low orbit NASA and other satellites. I have been playing around with wxsat reception for several years using modified filter scanners. The results have been acceptable but not great. This receiver is extremely sensitive. I have done away with an external pre-amp and using my 2 meter Oscar cross-yagi I am able to copy satellite images horizon to horizon. There are numerous free soundcard programs for wxsat image display. If your expensive satellite antenna array is sitting idle this little receiver will put it to good use. See the QST review.