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Reviews Categories | Specialized Amateur Communication Products | Misty Hollow DDS VFO FOR DRAKE TR-7 Help


Reviews Summary for Misty Hollow DDS VFO FOR DRAKE TR-7
Misty Hollow DDS VFO FOR DRAKE TR-7 Reviews: 3 Average rating: 4.7/5 MSRP: $$475
Description: A 3erd party after market DDS VFO for DRAKE TR-7/A and R-7/A
AND TR-5
Product is in production.
More info: http://www.mistyhollowenterprises.com
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K8AC Rating: 5/5 Nov 3, 2006 13:34 Send this review to a friend
A great update for the TR-7  Time owned: 0 to 3 months
Check out Misty Hollow's website for the technical details of the product. If you're going to order one of these, be patient as the maker doesn't always have an inventory of them and mine had to be built and tested. The short opinion is that it works as advertised and breathes new life into your old TR-7. The manual does a good job of documenting the functions and includes circuit diagrams. Here's what you get with the basic RB7500:

1. VFO
2. Operations Book
3. Cable for connection to the TR-7
4. Wall-wart 12VDC power supply

The VFO is housed in a black powder coated enclosure about the same width and height as the RV-7 VFO, but it's shorter than the RV-7. Besides the LCD readout, the front panel includes the main tuning knob, an array of 6 push-button switches, and one rotary switch for selecting the tuning rate. The fairly hefty black aluminum main tuning knob includes a finger dimple for rapid QSY.

The LCD shows you the VFO-A and VFO-B frequencies, the band (as a 500 KHz frequency range), tuning rate and mode (transceive or split). It's well illuminated and my only criticism of the display is that the current VFO frequency doesn't jump out at you from all the other text. On the other hand, the current VFO frequency is displayed on the TR-7 LEDs as with the RV-7. You change bands by pressing the TUNE/BND CHG button and turning the main tuning knob. Of course, you must also make sure you have the TR-7 set to the proper band segment.

The first thing I discovered when unwrapping the VFO is that you can't operate it from your station DC supply unless that happens to be 12V +/- .25V. If your supply is around 13.8VDC you'll need to use the included wall-wart supply, and that's what I did

The frequency accuracy of the VFO depends on the alignment of three oscillators in the TR-7. The manual warns that if those are off, then your VFO readout will not be correct. In my case, I was off less than 50 Hz and that's close enough for me. The tuning rate can be set at 1, 10 or 100 KHz per knob revolution and CW operators will now be able to enjoy the narrow filters without having to deal with the 25 KHz/revolution of the TR-7 VFO. It would have been nice to have a 3 or 5 KHz/revolution option but the rates provided are certainly adequate.

There's another version of the VFO with an additional circuit board and cable for controlling an R7 as well as the TR-7. This certainly isn't an inexpensive addition to your TR-7, but given the prices of the Drake RV-75 these days, it's a steal. For a while there was a nice alternative available from Woodbox Radio in Italy, but that appears to no longer be sold.

If your TR-7 is a shelf queen, then you really don't have need of the RB7500. If you operate CW and the digital modes, then you really do need this thing!


 
HB9TRD Rating: 5/5 Mar 11, 2006 08:39 Send this review to a friend
Almost indispensable  Time owned: 6 to 12 months
The stability of this VFO is amazing. Once you have tried it, you can no longer operate a TR-7 without it.
 
WA2JJH Rating: 4/5 Apr 4, 2005 02:12 Send this review to a friend
Drake 3erd party DDS VFO  Time owned: 0 to 3 months
The TR-7 is a great radio, even by todays standards. So good there are MIL variants.

Oh, but the drifty VFO(PTO). With the RV-75 selling for $700++, when you can get one, I am glad some third parties are making DDS VFO's for the TR-7/R-7A.

The sleepy hollow is PLUG&PLay.
Amazing to see how rock stable a TR-7 can be!
 


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