Recommended Service Monitor for Ham Radio Transceivers

[skatfamily]

I would like to purchase a service monitor to align and troubleshoot ham radio transceivers (HF through UHF/SSB, FM, etc.). I don't need it for cellular phones or pagers or commercial gear. Which service monitor would you recommend? Most of the ham radio service manuals call for a spectrum analyzer and some posts have said that alignment is much easier with a tracking generator (I would like an opinion on this). I know I will need one that does PLs. If I want to keep the cost reasonable, what used gear would you recommend?

Thanks, Scott AA6U

[Tom in D.C.]

Here is a current thread from this Board. Several service monitor threads have run in the past
and you can find them with a Board search.

http://batboard.batlabs.com/viewtopic.php?f=42&t=96166

For non-professional use, if you can find a Cushman CE6 in good operating condition,
properly adjusted and aligned, it might meet your needs. Cushman is out of business
but there are several shops that still specialize in them. There is also a Yahoo site.

[Andy Corbin]

I would like to purchase a service monitor to align and troubleshoot ham radio transceivers (HF through UHF/SSB, FM, etc.). I don't need it for cellular phones or pagers or commercial gear. Which service monitor would you recommend? Most of the ham radio service manuals call for a spectrum analyzer and some posts have said that alignment is much easier with a tracking generator (I would like an opinion on this). I know I will need one that does PLs. If I want to keep the cost reasonable, what used gear would you recommend?

Thanks, Scott AA6U

I saw Tom's reply and agree to a certain extent. The bugs you threw in were SSB/Spectrum Analyzer/Tracking Generator. The CE6 will not help you there. I HAD a Cushman CE50 with tracking generator, spectrum analyzer and SSB option but sold it. It was the only CE50 I have ever seen with a SSB option. It is true, a spectrum analyzer and tracking generator are nice to have but the main thing you will be doing with the TG function is duplexer alignment. For EVERYTHING you indicated you wanted, SSB, SA, and TG, you would probably want to go with an IFR1500. There are some IFR1200's that have the Spectrum Analyzer and Tracking Generator. Just gotta be careful and ask lots of questions.

I have an IFR500 which is a portable monitor. It is basically an IFR1000 without the scope. No TG or SA, but it does have SSB capability.

Another option I have seen are some of the HP units. No personal experience with them, but have some friends who are very pleased with their units. Many are reasonably priced and can handle the features you want. Some are "bench queens" and "portable" only because they have a handle on them, but still work pretty well.

Just my $.02 worth.

Andy

[tvsjr]

HP8924 for a bench queen (expect a hernia if you intend to transport).
HP8921 for a more transportable monitor.

My 8921 has aligned hundreds of radios up through current P25 gear, and I've been very pleased with it. It just works - and the user interface isn't intimidating (*cough*IFR1900*cough*).

[skatfamily]

Thanks for the advice. The problem I found in researching this topic is that a lot of people use them for commercial gear (which I am not) and there is no central archive comparing the features and options of the different models available. Your insight and experience was very valuable. Now I just need to find a good unit at a good price.

[skatfamily]

Another observation: I noticed no one recommended any Motorola units. Should I avoid them?

[skatfamily]

I looked up the specs for the HP 8924 and it seems that it is not really intended for use much below 30 MHz and I would be using it for HF rigs. The IFR 1500 looks like it is made to work the lower frequencies.

[d119]

skatfamily:

Keep this in mind - an amateur transceiver isn't much different from a commercial transceiver. This applies to both FM units and SSB units.

Basically an amateur transceiver does the same thing but with direct frequency entry and more bells and whistles.

What I'm trying to say is that service monitors were primarily designed to handle any form of radio, not just amateur radios. There is no specific service monitor for amateur radios.

I use a Motorola R2670 at work (love it), and a Motorola R2008 and an IFR 1500SA at home (love them too). I've aligned both amateur and commercial radios with all of them, and the only thing that differs is the controls on the monitor. The procedure is more or less the same.

My $0.02 - Get an IFR 1500. It'll do exactly what you want, wont cost TOO much, and it won't let you down.

[Andy Corbin]

Another observation: I noticed no one recommended any Motorola units. Should I avoid them?

I don't have any issues with Motorola monitors. I have an R2400 that works just fine. When I got the IFR1500, I kept the R2400 as a backup. I see an R2400 on Ebay now starting at $400. I don't know if they will go down into the HF portion. I would have to get my manual out and see. Mine will not do SSB.

I see some Wavetek's out there from time to time. Don't know much about them.

Unless you are interested in just the very basic functions with marginal performance, I would stay away from the Ramsey Com3 and the Helper units. They are small and lightweight but anything other than generating a signal of sorts into a radio or receiving a signal off the air, these units are pretty substandard compared to the HP's and IFR's.

Andy

[WB6DGN]

The HP 8924 is available with either a mechanical attenuator or an electronic attenuator. The units with the mechanical attenuator are accurate from about 200kc (if I remember correctly) to 1000Mc while the units with the electronic attenuator are speced. as accurate from 30Mc to 1000Mc. In this instance accuracy refers to input/output LEVELS, not frequency or modulation, etc. The electronic attenuator was a newer revision because it was found to be more reliable with heavy commercial usage. For more information see the Amtronix website at: http://www.amtronix.com/. That said, I use my 8924C with the electronic attenuator on HF and lower frequencies (eg. to generate a 455kc IF frequency and to listen to AM radio stations) and have made a small chart showing the approximate level error at the frequencies I use most often. For that matter, if I did much HF work, I wouldn't use a service monitor at all. I would buy a good signal generator (such as an HP 8640 or 8657) which is much more versatile for non FM receiver servicing anyhow and most service monitors, even if they can generate and receive SSB, are very limited in the number and type of measurements that can be made. Put another way, NO service monitor that I know of is really intended as a comprehensive service tool for MF/HF equipment.
Tom DGN

[skatfamily]

Interesting thoughts that I very much appreciate. In looking at the specs I could find for the service monitors mentioned, it appears that the IFR 1500 and HP 8920 meet the criteria I need.

I looked at the service manual for my Yaesu 736R VHF/UHF rig and it requires a spectrum analyzer and a tracking generator for alignment. My Icom 765 HF rig only requires a spectrum analyzer but not a tracking generator.

I have an HP 8640B signal generator and use it extensively. It's just that the service monitors have other important functions that I don't currently have and are often needed for servicing ham equipment (HF and up). Now my task seems to be waiting to find a reasonably priced functional unit.

[Wowbagger]

I'd also suggest looking at the COM-120B or C, with the SSB hardware option.

[skatfamily]

Thanks. I'll put the Com 120 B or C on my list. Someone has a Com 120A on eBay right now, but it looks like it has some issues.

[Andy Corbin]

Interesting thoughts that I very much appreciate. In looking at the specs I could find for the service monitors mentioned, it appears that the IFR 1500 and HP 8920 meet the criteria I need.

I looked at the service manual for my Yaesu 736R VHF/UHF rig and it requires a spectrum analyzer and a tracking generator for alignment. My Icom 765 HF rig only requires a spectrum analyzer but not a tracking generator.

I have an HP 8640B signal generator and use it extensively. It's just that the service monitors have other important functions that I don't currently have and are often needed for servicing ham equipment (HF and up). Now my task seems to be waiting to find a reasonably priced functional unit.

The 1500 is a good box. Just be aware, I have heard the mechanical (dial type) attenuators can get flaky with that model. Just make certain if you get serious about a 1500 you check on that. Mine has the digital electronic attenuator and is fine. The "downside" to the digital attenuator is it reads only in dbm and cannot be toggled to microvolts.

[Wowbagger]

Thanks. I'll put the Com 120 B or C on my list. Someone has a Com 120A on eBay right now, but it looks like it has some issues.

You don't want an A - much older CPU, older software, slower. It won't have the offset tracking generator option, it might not have the second full-function function generator, it won't have the graphics speed-ups.

You want the B or C (the difference being the C has an LCD rather than the Planar EL display).

[lc4600]

Being an older post ,Comment I would caution the use of the COM-120A or COM-120B for Ham radio repair. The COM-120A/B is a frequency locked unit-not a phase locked unit and the generated carrier will sound and look wobbly out of the product detector in upper and lower SSB of the UUT. NØPXJ Aeroflex

[Wowbagger]

Carl (N0PXJ, user lc4600) does indeed work here at Aeroflex Wichita, as a technician of MANY decades (as in, more than me!). Mods - you may want to give him the Aeroflex tag too.