Crystal options for old ham gear like Regency HR-2B?

[needairtime]

Have most people dropped their old gear like the Regency HR-2Bs? I got this radio fairly cheap and is my only 2m radio. I was wondering if I can get it working with the local club repeater. Unluckily, don't have the right crystals.

I'm wondering what I can do to deal with not having crystals needed to tune to specific frequencies. I was initially thinking about designing a(/dual) PLL(s) for it with an artificial constraint to keep the "classic" gear as close to stock as possible "drop in and go", but now thinking there will be too many changes to the hardware needed for this to work.

Coupled with the fact I can get a Baofeng for cheaper than a pair of crystals for a ONE specific frequency... but that's not the spirit of amateur radio(!)

At least I did overhear someone once talking over 70cm about needing crystals for some radio, likely something over 10m, alas I'm not licensed yet so I didn't respond. So there seems to still be a demand for crystals?

 

[rfradioconsult]

Aside from the required crystals you will most likely need a method to generate a low level sine wave audio signal a.k.a. CTCSS or PL to enable the repeater which is transmitted whenever you key the mic. The HR series were not known for their receiver performance, they were very susceptible to other signals and interference. A nice radio for your museum shelf but waay past it's prime, think early 70's

 

[Voyager]

There is a company in the UK making quality, but inexpensive crystals.

I think this might be it: http://www.quartslab.com/
(ignore the mis-spelling of quartz)

S/H isn't too bad either.

Have you checked eBay for the required frequencies?

 

[Fast1eddie]

Bomar and International Crystal still in business??? I recently cleaned up a Drake TR-33 and have it on the air. Old School!!

Currently working on building a time machine to transport me back to the 70's....

 

[needairtime]

I figure that I may have to resort to self- or custom-ground crystals if I really needed it to work and unfortunately that's not cost effective. The CTCSS I figure I can easily work around as generating tones is a lot easier than generating fixed frequency RF (plus the local repeater uses 100.0 Hz, and without a fractional frequency, it's a lot easier to generate - was going to see if I can use my DDS to generate that tone once I figure out the RF generation.)

I did hear about the HR's poor selectivity which is a bit weird as it is a superhet, and a bit expected (since it's not PLL). I was looking into how the circuit was designed and the frequency multipliers probably has something to do with it; I can't imagine the LO waveform to be perfect though it is the correct frequency - but has a lot of weird harmonics in it that may mix properly with adjacent channels. Oh well, I'm going to ignore that for now and want to get it to work...

 

[Voyager]

Bomar and International Crystal still in business???

Still in business but they no longer sell "one offs".

 

[wyShack]

I think Jan Crystals is still in business-http://www.jancrystals.com/. Otherwise you are going to have fun. A PLL circuit would be the easy way-but would still need at least one crystal for the reference oscillator. Also would either need some fast switching or a PLL for receive and one for transmit- can't even remember what the multiplier is-hope you have the manual.

The old rockbound receivers were considerably 'tighter' than today's broadband gear -most of the front ends were tuned to just the 146-148 range so the 1st RF stage could be quite selective.

73

 

[Voyager]

Actually, synthesizing a crystal radio is perfectly in the ham spirit, and is an interesting endeavor. It's been done many times, but not with a Regency that I recall. You can go as fancy or as simple as you want - from full band control and memories to a crystal replacement only.

 

[needairtime]

Yeah, that's why I was thinking about designing/building a synthesizer for the HR2B - Buying crystals is not "really" in the spirit, buying a Baofeng is clearly is not in the spirit.

Grinding crystals is, however Alas I doubt I can grind a crystal that accurately especially if I'm starting with a HC49U, too tiny to work with, and it'll be ridiculous if I have to grind two per channel if I could build a synthesizer and effectively get all the crystals I'll ever need. Though I may still need to grind one crystal to simplify the synthesizer...

 

[Voyager]

Wow you are a glutton for punishment (grinding your own crystals). How are you going to make sure the crystal is pure enough and won't have unintended spurs? Is grinding your own crystals really advancing the state of the art?

 

[needairtime]

Yeah, I really can't get myself to grind my own crystals. And no it's not really advancing state of the art, rather it's a skill that is helpful - if you can't simply (or simply can't) buy what you need.

I was speccing out what I'd need for the PLL based on the current HR2B design, it isn't going to be pretty with an off-the-shelf crystal. Having that "perfect" crystal simplifies the PLL immensely.

I sure hope my frequency counter is accurate. Definitely will need to utilize it before I try to transmit with the synthesizer...