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DRAKE R8B
Communications Receiver

Software & Tips

One of the hottest and most popular shortwave receivers around are the Drake R8 series radio manufactured by RL Drake.

But there is more that can be done with this radio!

Software

To really make these radios sing a software control package is essential. The package that I have found works the best for me is the SMART R8 Control by
Fineware. Economically priced, the Smart R8 Control gives me complete control over the R8. There are too many features to mention but some of my favorites are:

Selectable Band Scan with Spectrum Analyzer.
Complete manipulation of logs, and
CumbreLite supplement.
Easy control over memories and alphanumeric display. (the R8B has 1000 memories!)
Excellent shortwave broadcast schedule database.

Download my memories for the R8B. *Note you must be using the Fineware Smart R8 Control program and have an R8B to use this file. Let me know if you would be interested in sharing your memories.

Mods & Tips
I have not seen a lot of modifications for the R8. Perhaps it is because Drake got it right with the R8. My biggest gripe with the R8 is it's VFO (tuning knob). When tuning around the VFO lacks a flywheel effect and the knob feels very light. Thanks to the Drake R8 Listserv someone recommended the following tip. (Sorry I don't remember who it was)

VFO Modification for smoother tuning. Its very simple, remove the VFO tuning knob from the R8. It is does not come off very easily and requires some hard pulling. Fill the inside of the knob with lead shot and epoxy over the to hold the lead BBs in place. Make sure not to get the epoxy over the hole that plugs back into the radio. Let the epoxy dry and push the knob back on the radio. It's very easy and you will notice a big difference in how much smoother the knob turns. While you won't get a true fly wheel effect, the modification does make a difference.

FROM REC.RADIO.SHORTWAVE
From: RadioGuy (nospam@nospam.com)
Subject: Drake R8B --- Encoder Repair Notes
Newsgroups: rec.radio.shortwave
Date: 2003-01-22 16:18:05 PST

I finally got around to fixing the encoder problem (erratic tuning) that's been bothering me for awhile.

Removal of the encoder board from the front panel was fairly straightforward; just time consuming. The inner and outer panel came apart surprisingly easy and making the repair somewhat enjoyable; re-assembly wasjust as easy.

My first attempt was to unsolder the encoder from the board. However, like many of you, I bent back the tabs of the encoder with a small screwdriver and pulled it apart for servicing. Even though I had a replacement encoder it was difficult to unsolder the part from the board---plated through holes! It might be that replacement of the entire encoder would be required at some later date anyway.

As I had mentioned in a previous post, I was interested in learning why the encoder failed. After removal of the encoder wheel from the body of the encoder I examined the contact surfaces under stereo microscope (Leica SZ-4) at 40X magnification. I could plainly see what appeared to be normal wear patterns in the conductive surfaces that matched the position of the contact fingers in the mating part.

The contact fingers were examined next. Using similar magnification and upon carefully rotation of the part, I could plainly see that the contact points were worn through their silver plating and well into the brass base metal. The contact surfaces were burnished to a bright, mirror finish. Furthermore, the first two contact points were clean with a clear grease
residue while the third inner contact (electrical common?) had a dark brown/black greasy residue about its contact surface.

With the realization that I rarely used the tuning knob I wanted to understand why the wear on the contact fingers seemed, in my opinion, excessive. I observed that the third contact finger (electrical common?), the one with the dark residue, was in continuous electrical contact with the wheel more so than the other two fingers that rode on the 'spokes' of the wheel. Furthermore, the surface that the contact was moving against had a rough surface consisting of striated tooling marks with uniform depth and spacing that suggested the result of rough polishing or grinding. Close study of the wear patterns on the wheel clearly revealed hills and valleys and that the hills were the surfaces that had been worn into the wheel by that contact finger but had not yet reached the depth of the valleys. It was this observation that led me to think that the brown/black residue on this particular contact was an accumulation of silver and brass particulate
from the contact finger and wheel that had oxidized and mixed with the grease. The rough surface of the wheel was simply acting as an abrasive surface and was wearing the contact points.

I thought I would reuse the old encoder and see how long it would last after a bit of maintenance. I cleaned the encoder with electrical solvent cleaner and with the help of a very fine brush I cleaned the contact fingers as well. The parts were carefully blown dry then re-examined under the scope and were found clean. A small drop of DeoxIT contact cleaner was placed on the wheel surfaces then worked by pressing the assembly together and rotating the wheel against the contacts.

There was another problem with the encoder that I need to take care of as well. Ever since I got this receiver I had been bothered by the viscous, squishy feel of the tuning knob. While I had the encoder opened I carefully cleaned it of all grease with electrical cleaner. The designers of the encoder had used a relatively large quantity of grease to gain the damping action that had bothered me. On the reverse side of the wheel (shaft end) the grease was easily removed with a probe and the remainder was readily soluble in the electrical solvent. However, before re-assembly, I placed a
very light film of fine grease on the shaft. After the front panel was replaced I placed a small felt washer on the encoder shaft. The knob was positioned against the felt washer to get the desired feel. Now the knob turns with a dry, positive, precise, clean feel with no wobble or endplay. Furthermore, I replaced the R8B knob with that of the R8---the aesthetic enhancement that the old R8 knob adds to the receiver is remarkable!

While the front panel was detached from the chassis, I also removed all controls and added a drop of DeoxIT into them and worked it in. The tone control was beginning to get scratchy and I've had a problem with the volume control in the past.

In the process of working on the front panel I learned how the readouts are backlit---just a bunch of green LED's on a circuit board. I have always been upset by the lime-green color of the display. Drake had been known for decades for their use of a distinctive blue for illuminating the meter and dial displays of their older equipment and I liked it very much. I guess when the receiver was designed there weren't any blue or white LED's and those that are available now are expensive. I intend to experiment with blue and white LED's as well as blue filters. The closest filter color I had on hand to match the Drake blue on my vintage pieces of Drake gear is the blue tab on 3-ring binder notebook separators or hanging file tabs. I' ll take a tab to the art supply shop and see if I can match it.

The receiver has been re-assembled and everything is working properly; tuning is as it should be. It will be interesting to see how long the repaired encoder lasts. I had the encoder replaced under warranty repair by Drake twice before.

In summary; apparently the encoder failed as a result of intermittent electrical contact resulting from dirty contact surfaces. Others have suggested contact bounce and poor electrical design. My personal opinion, although based on this one example and comments from others, suggests that the encoder is poorly designed or not able to take the continuous wear and tear it experiences in its application as a main tuning control for a radio receiver. Quite possibly it should be replaced with a part more suited to the task.

R.

 

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