View Single Post
  #8   Report Post  
Old June 10th 07, 06:03 PM posted to rec.radio.cb
Leland C. Scott Leland C. Scott is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 44
Default Modulation on scope question

James;

One of the problems buying used test equipment is the manufacture finds
there is some weakness in the design resulting in frequent failures, one
reason why they may quit manufacturing it.

I don't know if the HP signal generator you mentioned is one such item. I
remember in some back issues of QEX somebody came up with a modification to
replace a section in the output of a HP signal generator that was known to
be particularly failure prone, the original part used isn't available
anymore if I remember right.

Others have picked up old Tech scopes real cheap that had problems, hoping
to fix them, and finding out that the blown parts, like Tunnel Diodes, are
now almost imposable to find since almost nobody makes them anymore. And the
ones that do, if you can find the exact one you need, want such a high price
for them it isn't worth it.
--
Regards,
Leland C. Scott
KC8LDO


"james" wrote in message
...
On Wed, 06 Jun 2007 18:55:21 -0400, Vinnie S.
wrote:

+++On Wed, 06 Jun 2007 15:21:49 GMT, james wrote:
+++
+++On Sun, 03 Jun 2007 21:29:09 -0400, Vinnie S.
+++wrote:
+++
++++++I am restoring an old TRC-455, and want to align it by Sams. I
have a Tek scope,
++++++but a standard 10x probe. Do I need a probe with a certain
bandwidth?
++++++
++++++Vinnie S.
+++*************
+++
+++A scope probe with 50 MHz bandwidth will be suficient. The bandwidth
+++of the probe is stated so that you will avoid attenuation issues at
+++high frequencies. Measurements above the rated bandwidth of the scope
+++probe will yield inaccurate measurement levels. If you are just
+++looking for the presence of a signal and the absolute level is not
+++needed then don't worry to much about the bandwidth of the scope
+++probe.
+++
+++james
+++
+++
+++I just wanted to measure modulation on a TRC-455 that I am restoring. I
have a
+++10x probe with the bandwidth being 60Mhz in the 10x position.
+++
+++But I have bad news. I apparently need and RF generator for alignment
of the
+++receiver. I do not own one. I have everything else. So off to ebay I
go. Any
+++recommendations?
+++
+++Vinnie S.

*****************

I have an HP 8656 generator. A bit pricy even still today. I got mine
at a fantastic price 8 yrs ago. Bought it when the factory was closing
down and moving as excess equiptment for around $400. They are still
commanding around $700 to $1000.

Really for CB work if you can find any of the older B&K CB test
equiptment in decent shape I would suggest those. Equiptment like HP,
Wavetek, and others are very pricy for home test equiptment.

james