Gary
The most useful test probe for general troubleshooting is a standard O-Scope probe. Granted, their native impedance, 1M or 10M, can induce attenuation of RF signals, but in most cases, this is not a significant problem as accurate measurement of the RF level is not necessary, you are simply trying to verify its existence or adjust it for max amplitude. The flexibility of an O-Scope probe gives you a clip on grabber, or you can remove that and use the pointed tip. It also affords a close parallel ground terminal that will help significantly in reducing induced RF noise.
For difficult to access test points, I use fine tip grabbers with a wire lead, attach the grabber, clip them to the test point, then attach the scope probe to the wire.
See the following links. You can get a kit with grabbers and leads, from Amazon, very useful, but the clips are a bit fragile.
See the following links. You can get a kit with grabbers and leads, from Amazon, very useful, but the clips are a bit fragile.
The gold standard are grabbers manufactured by Tektronix and HP, but they tend to be available only in quantity to support logic analysis and are typically pricey. Still, well worth having in your test bench kit.
For RF level measurements, it is important to match the impecance of the test point with the test instrument port. I use a 50 ohm coaxial test leads with dual grabbers on one end, BNC male on the other for direct connection to the test equipment. These are common test leads available from many sources. Most are RG58 coaxial cable, which is a bit stiff, I prefer this one from Pamona Electronics with more flexible RG174.
If you find you will be working on Japanese radios produced by Kenwood, Icom, Yaesu, you will find that internal RF signals are often routed via coacial cables terminated with Taiko Denki connectors. These present a challengy for signal monitoring. I used to obtain custom test cables and loose connectors from the RF Connection, the only US based supplier of these now obsolete connectors, but they are no longer in business. Jeff Hilliard, K6IOK, acquired their stock and now provides these test cables. I find these test cables to be indespensible.
https://k6iok.com/products/ols/categories/test-cables
https://k6iok.com/products/ols/categories/test-cables
--
________________
73's
Dave - KB7JS
73's
Dave - KB7JS
_._,_._,_
Groups.io Links:
You receive all messages sent to this group.
View/Reply Online (#95471) | Reply to Group | Reply to Sender | Mute This Topic | New Topic
Your Subscription | Contact Group Owner | Unsubscribe [jhjoshan@gmail.com]
_._,_._,_
No comments:
Post a Comment